Updated

Cairo, Mar 22 (Reuters & Agencies): ISIS claimed responsibility for attacks on Brussels airport and a rush-hour metro train in the Belgian capital on Tuesday which killed at least 30 people, a news agency affiliated to the group said.

The Amaq agency said suicide bombers from the group, strapped into explosive belts, had staged both attacks. Belgian media said police were hunting one attacker who had survived.

The coordinated assault triggered security alerts across Europe and drew global expressions of support, four days after Brussels police had captured the prime surviving suspect in ISIS's attacks on Paris last November.

A witness said he heard shouts in Arabic and shots shortly before two blasts struck a packed airport departure lounge at Brussels airport.

Meanwhile, Belgian authorities published surveillance camera images of three suspects in the attack on Brussels airport on Tuesday, Belga news agency reported.

Belgian media published a security camera picture of three young men pushing laden luggage trolleys through the airport and reported that police suspected them of being the attackers. They said two were suspected of having blown themselves up while police were hunting the third.

Amaq carried the claim of responsibility several hours after the morning attacks. "Islamic State fighters opened fire inside Zaventem Airport, before several of them detonated their explosive belts, as a martyrdom bomber detonated his explosive belt in the Maalbeek metro station," it said.

Austrian Horst Pilger, who was awaiting a flight with his family when the attackers struck, said his children had thought fireworks were going off, but he instantly knew an assault was underway.

"My wife and I both thought 'bomb'. We looked into each other's eyes," he told Reuters. "Five or 10 seconds later there was a major, major, major blast in close vicinity. It was massive."

Pilger, who works at the European Commission, said the whole ceiling collapsed and smoke flooded the building.

US President Barack Obama led calls of support to Belgian Prime Minister Charles Michel after Brussels went into a state of virtual lock-down.

"We must be together regardless of nationality or race or faith in fighting against the scourge of terrorism," Obama told a news conference in Cuba. "We can and we will defeat those who threaten the safety and security of people all around the world."

Michel spoke at a Brussels news conference of a "black moment" for his country. "What we had feared has come to pass."

The blasts occurred after the arrest in Brussels of a suspected participant the Paris attacks that killed 130 people. Belgian police and combat troops on the streets had been on alert for reprisal but the attacks took place in crowded areas where people and bags are not searched.

Transport Shut Down

All public transport in Brussels was shut down, as it was in London during 2005 Islamist militant attacks there that killed 52. Authorities appealed to citizens not to use overloaded telephone networks, extra troops were sent into the city and the Belgian Crisis Centre, clearly wary of a further incident, appealed to the population: "Stay where you are".

Brussels airport will remain closed on Wednesday, its chief executive Arnaud Feist told reporters.

Public broadcaster VRT said police had found a Kalashnikov assault rifle next to the body of an attacker at the airport. Such weapons have become a trademark of Islamic State-inspired attacks in Europe, notably in Belgium and France, including on Nov. 13 in Paris.

An unused explosive belt was also found in the area, the public broadcaster said. Police were continuing to scour the airport for any further bombs or attackers.

Alphonse Youla, 40, who works at the airport, told Reuters he heard a man shouting out in Arabic before the first explosion. "Then the glass ceiling of the airport collapsed."

"I helped carry out five people dead, their legs destroyed," he said, his hands covered in blood.

A witness said the blasts occurred at a check-in desk.

Video showed devastation in the hall with ceiling tiles and glass scattered across the floor. Some passengers emerged from the terminal with blood spattered over their clothes. Smoke rose from the building through shattered windows and passengers fled down a slipway, some still hauling their bags.

Public broadcaster RTBF said police were searching houses in the Brussels area.

A Crisis Centre spokesman issued provisional figures of 20 killed in the metro and 10 at the airport. Public broadcaster VRT had said earlier 20 were killed in the train and 14 at the airport.

Many of the dead and wounded at the airport were badly injured in the legs, one airport worker told Reuters, suggesting at least one bomb in a bag on the floor.

Britain, Germany, France and the Netherlands, all wary of spillover from conflict in Syria, were among states announcing extra security measures. Security was tightened at the Dutch border with Belgium.

The blast hit the train as it left Maelbeek station, close to European Union institutions, heading to the city centre.

VRT carried a photograph of a metro carriage at a platform with doors and windows completely blown out, its structure deformed and interior mangled and charred.

A local journalist tweeted a photograph of a person lying covered in blood among smoke outside Maelbeek metro station, on the main Rue de la Loi avenue which connects central Brussels with the EU institutions. Ambulances were ferrying the wounded away and sirens rang out across the area.

"We are at war"

"We are at war and we have been subjected to acts of war in Europe for the last few months," French Prime Minister Manuel Valls said.

Brussels airport said it had cancelled all flights until at least 6 a.m. (0500 GMT) on Wednesday and the complex had been evacuated and trains to the airport had been stopped. Passengers were taken to coaches from the terminal that would remove them to a secure area.

All three main long-distance rail stations in Brussels were closed and train services on the cross-channel tunnel from London to Brussels were suspended.

Security services have been on a high state of alert across western Europe for fear of militant attacks backed by Islamic State, which claimed responsibility for the Paris attack.

While most European airports are known for stringent screening procedures of passengers and their baggage, that typically takes place only once passengers have checked in and are heading to the departure gates.

Although there may be discreet surveillance, there is nothing to prevent members of the public walking in to the departure hall at Zaventem airport with heavy baggage.

Following an attempted ramraid attack at Glasgow Airport in 2007, several airports stepped up security at entrances by altering the pick-up and drop-off zones to prevent private cars getting too close to terminal buildings.

European stocks fell after the explosions, particularly travel sector stocks including airlines and hotels, pulling the broader indices down from multi-week highs. Safe-haven assets, gold and government bonds rose in price.

The attacks appeared to be linked to the arrest of French citizen Salah Abdeslam - the prime surviving suspect for the Paris attacks on a stadium, cafes and a concert hall - who was captured by Belgian police after a shootout on Friday.

Belgium's Interior Minister, Jan Jambon, said on Monday the country was on high alert for a revenge attack.

It was not clear what failings if any allowed the plan for Tuesday's operation to go ahead and whether the double attack was planned in advance or put together at short notice.

"We know that stopping one cell can ... push others into action. We are aware of it in this case," Jambon said.

Earlier update

Brussels, Mar 22 (AFP): A string of explosions rocked Brussels airport and a city metro station today, killing at least 34 people, according to media reports, as Belgium raised its terror threat to the maximum level.

Two explosions targeted the main hall of Zaventem Airport at around 8:00 am (1330 IST), with a third hitting the Maalbeek metro station, near the European Union's main buildings, just as commuters were making their way to work in rush hour.

Belgian media reports said at least 34 people had been killed and 35 injured at the airport, while an AFP reporter said at least 15 people with bloodied faces were being treated by emergency services outside the metro station.

The blasts come days after the dramatic arrest in Brussels on Friday of Salah Abdeslam, the prime suspect in the Paris terror attacks that killed 130 people in November, after four months on the run.

There were chaotic scenes at the airport as passengers fled in panic, with a thick plume of smoke rising from the main terminal building. The blasts smashed the windows of the departure hall and sent ceiling tiles shattering to the floor. Witnesses told Belga news agency there had been shots and shouts in Arabic at the airport before the blasts hit at the airport on the northwest outskirts of Brussels.

"There have been two explosions at the airport. Building is being evacuated. Don't come to the airport area," the airport said on Twitter, as police cars and rescue vehicles rushed to the scene.

"All airport operations have been suspended until further notice," it said. Interior Minister Jan Jambon announced that Belgium's terror threat had been raised from three to a maximum of four. Airports in neighbouring France, Germany and the Netherlands as well as Britain swiftly boosted security in response.

The blasts triggered a transport shutdown in Brussels, with all flights halted in and out of the airport and the city's metro, tram and bus services suspended. European Union staff in Brussels, where the 28-nation bloc has its headquarters, were told to stay indoors or at home.

Sweden's Prime Minister Stefan Lofven branded the blasts an "attack against democratic Europe", while British premier David Cameron tweeted: "I am shocked and concerned by the events in Brussels. We will do everything we can to help." "We heard the explosion and felt the blowback," Jean-Pierre Lebeau, a French passenger who had just arrived from Geneva, told AFP, adding that he had seen wounded people and "blood in the elevator".

"First we were kept together by the border police, then they gave us the order to evacuate," Lebeau said. The ceilings collapsed, he said, describing a smell of gunpowder at the scene.

With shock on their faces, Jean-Pierre Herman embraced his wife Tankrat Paui Tran, who he had just gone to collect from the airport after her flight from Thailand. "My wife just arrived," Herman said. "I said hello, we took the elevator and in the elevator we heard the first bomb.

"The second exploded just when we got off. We ran away to an emergency exit. I think we are very lucky." An AFP correspondent on their way to the airport said roads to the terminal had been blocked and trains halted.

Charlotte McDonald-Gibson, a British journalist living in Brussels, told AFP there had been "total confusion" at the airport, where she was having breakfast. "Suddenly staff rushed in and said we have to leave," she said.

"They rushed out and into the main terminal A departures building. Nobody knew what was going on. "It was total confusion, people were just standing around wondering what was happening." There was no immediate confirmation of the cause of the blasts.

Europe's main stock markets retreated as the news broke, with London's benchmark FTSE 100 index dropping 0.6 per cent compared with yesterday's close and Frankfurt's DAX 30 shedding 1.1 per cent.

Earlier Update:

Three suicide bomb attacks at Brussels airport, Metro station - 23 Killed, several injured

At least 23 dead after 'suicide bombers' attack American Airlines check-in desk at Brussels Airport - as SECOND 'terror attack' hits Metro station near EU headquarters

• Shouts 'in Arabic' heard before two explosions went off near the American Airlines check-in desk at 8am (7am GMT)
• Terrified passengers covered in blood ran for their lives after explosion sent 'shockwaves' through terminal building
• Reports of another explosion at a Metro station near the EU headquarters in the Maelbeek area of central Brussels
• Evacuated passengers are being ferried onto buses and are being driven to a 'crisis centre' away from the airport
• Comes a day after Belgium minister warned of revenge attacks after arrest of Paris attacks suspect Salah Abdeslam

Brussels, Mar 22 (Daily Mail) : At least 23 people have been killed and dozens injured in Brussels after a series of terror attacks struck the city's airport and a metro station near the EU headquarters.

Witnesses described apocalyptic scenes with blood and 'dismembered bodies everywhere' after two blasts rocked the American Airlines check-in desk at Brussels Airport at 8am (7am GMT) in a suspected suicide bombing. At least 13 people have died and 35 were injured.

Around 90 minutes later, ten people are believed to have been killed when an explosion hit a Metro station just 400 metres from the EU headquarters in the city centre in another suspected terror attack.

The explosions come just a day after the Belgium Interior Minister warned of possible revenge attacks after the arrest of Paris massacre suspect Salah Abdeslam in the city last week.

At the airport, shouts in Arabic were reportedly heard before the explosions which sent shockwaves through the terminal building, shattering windows, knocking roof tiles off the ceiling and sending terrified passengers running for their lives.

Samir Derrouich, who works at a restaurant in the airport, told : 'The two explosions were almost simultaneous.
'They were both at check-in desk. One was close to the Starbucks. It was awful. There was just blood. It was like the apocalypse.'

Flights due to land at Brussels-Zaventem, which handles 21million passengers a year, were sent to Antwerp, Liege, and Brussels Charleroi airports.

Europe's biggest airports are all increasing their security today. Heathrow confirmed it had stepped up its own 'visible' security in the wake of the attacks – with large units of armed police patrolling the airport this morning.

The Belgian Interior Minister has raised the country's security level to 'maximum' this morning as it prepares itself for more terror attacks in the wake of the airport bombings.

British Prime Minister David Cameron offered his support to victims and called a COBRA emergency committee meeting to address the events in Brussels.

He tweeted: 'I am shocked and concerned by the events in Brussels. We will do everything we can to help.

'I will be chairing a COBRA meeting on the events in Brussels later this morning.'

The incident came as the Belgian capital was on a state of high alert following the arrest of Paris terror attack suspect Salah Abdeslam in the city last week.

Belgium's Interior Minister, Jan Jambon, said the country was on high alert for a possible revenge attack following the capture of 26-year-old Salah Abdeslam in a flat in Brussels on Friday.

'We know that stopping one cell can... push others into action. We are aware of it in this case,' he told public radio.

Earlier:

Brussels Zaventem airport rocked by two explosions

Brussels, Mar 22 (Agencies) :  Several people were killed in the explosions that tore through the departure hall of Brussels airport on Tuesday, said Belgium’s public broadcaster RTBF.

The agency said shots were fired and there were shouts in Arabic shortly before the explosions.

The blasts occurred four days after the arrest in Brussels of a suspected participant in November militant attacks in Paris that killed
130 people. Belgian police had been on alert for any reprisal action.

•1.57pm - Explosion reported at Brussels Metro station close to EU institutions. No official confirmation.

•1.48 - Belgian fire service tells local media least several dead

Social media showed pictures of smoke rising from the departure hall where windows had been shattered by the blasts. Passengers were seen running away down a slipway.

Sky News television’s Alex Rossi, at the scene, said he heard two “very, very loud explosions”.

“I could feel the building move. There was also dust and smoke as well...I went towards where the explosion came from and there were people coming out looking very dazed and shocked.”

“The thinking here is that it is some kind of terrorist attack - that hasn’t been verified by any of the authorities here at the airport.”

Belgian interior minister said the terror alert has been raised to the maximum level in wake of the explosions.
Video showed devastation inside the departure hall with items scattered across the floor.

Belgian media said rail traffic to the airport was suspended.

Brussels airport said it had cancelled all flights and the complex had been evacuated.

Salah Abdeslam, the prime surviving suspect for November’s Paris attacks on a stadium, cafes and a concert hall, was captured by Belgian police after a shootout on Friday.

Belgium’s Interior Minister, Jan Jambon, said on Monday the country was on high alert for a possible revenge attack following the capture of 26-year-old Abdeslam.

“We know that stopping one cell can ... push others into action. We are aware of it in this case,” he told public radio.

French investigator Francois Molins told a news conference in Paris on Saturday that Abdeslam, a French citizen born and raised in Brussels, admitted to investigators he had wanted to blow himself up along with others at the Stade de France on the night of the attack claimed by Islamic State; but he later backed out.