Paris, Jan 10 (IANS): At least 500 extra troops are being deployed around Paris after three days of terror in the French capital left 17 people dead.

Interior Minister Bernard Cazeneuve said all necessary measures were being taken to protect the country, BBC reported.

Police in France are hunting for any accomplices of three gunmen killed by police Friday after two sieges.

Tens of thousands of people have taken part in silent marches to remember the victims in Nice, Pau and Orleans.

President Francois Hollande has warned the danger was not over yet.

"We have to be vigilant. I also ask you to be united - it's our best weapon," said Hollande in a televised address Friday night.

After a cabinet meeting Saturday, Cazeneuve said France would remain at its highest state of alert "for the next few weeks" and promised tight security for a massive unity march in Paris Sunday.

Those set to attend Sunday's unity rally include UK Prime Minister David Cameron, German Chancellor Angela Merkel, Turkish Prime Minister Ahmet Davutoglu, Spanish Prime Minister Mariano Rajoy and Russian Foreign Minister Sergei Lavrov.

"Sunday, the French people will cry out their love of liberty," said Prime Minister Manuel Valls.

France would be "firm and relentless in the face of the enemies of liberty", he added, urging all people to "assume their responsibilities".

The terrorist attacks started Wednesday when two brothers killed 12 people and injured 11 in an attack on the offices of satirical magazine Charlie Hebdo.

On Friday, Cherif and Said Kouachi were killed by police in Dammartin-en-Goele, 35 km north of Paris, as they emerged from a besieged warehouse building firing at police.

One hostage had been released earlier and a second employee, who was hiding in the building's cafeteria, was freed by police.

Police shortly afterwards launched an assault on a supermarket in Paris, killing Amedy Coulibaly and rescuing 15 hostages. They found the bodies of four hostages who are believed to have been killed before the assault. These victims have not yet been identified.

Police are searching for Hayat Boumeddiene, who was said to be with Coulibaly when a policewoman was killed in Paris Thursday, and is described as "armed and dangerous".

France's chief prosecutor Francois Molins said the investigation would "focus on determining who their accomplices were, how these criminal actions were financed and all the instruction and help they may have benefited from whether in France or from overseas".

He said 16 people had been detained for questioning, including the wife of one of the Kouachi brothers.

Prosecutors said the two brothers in Dammartin had a rocket launcher primed and ready to fire, while the supermarket in Paris had been booby-trapped with explosives.

Security officials have said they were aware of Coulibaly and the two brothers. Said Kouachi was known to have travelled to Yemen in 2011.

Both brothers are understood to have been on UK and US watch lists.

While holed up in the warehouse north of Paris, Cherif Kouachi phoned a French TV news network and told them he was acting on behalf of the Yemen branch of al-Qaeda (AQAP), having been financed by its leader Anwar al-Awlaki before he was killed by a US drone strike in Yemen in 2011.

The extremist group released an audio message late Friday praising the attacks but stopped short of claiming responsibility.