AP
 
Lucknow, Aug 19: The UP Police have heightened security around the Taj Mahal after receiving a letter threatening to blow up the monument, officials said Friday.

Sandbag bunkers have been set up outside the towering entrance gates leading to the 17th century monument and soldiers belonging to an anti-terrorist squad have been posted on 24-hour duty, said Ashok Kumar, a senior Uttar Pradesh government official.

Police were investigating a handwritten letter purportedly sent by an al-Qaeda supporter, saying the terrorist group planned to carry out blasts at the Taj Mahal.

Police were sceptical about the letter, but had begun investigations, Kumar said Friday.

"Police are verifying the source of the letter," he said. "The letter could be false but we cannot afford to be complacent. We are not taking any chances and have enhanced security at the Taj."

"The letter, signed by someone calling himself Mohammed Mirza and claiming to be associated with the al-Qaeda, was received at the office of the superintendent of police in Agra on Thursday," Kumar said.

"The letter said the al-Qaeda had plans to carry out blasts at the Taj Mahal and around busy markets of Agra," he said.

Meanwhile, as part of the new security drill, tourists have been warned not to carry any liquids, including bottles of mineral water, to the fabled white marble structure, located in the city of Agra, 130 miles from New Delhi.

At least 100 additional paramilitary soldiers armed with automatic weapons have been posted at strategic points on the outer periphery of the Taj Mahal complex, said a top police officer.

Police have also begun work on a dossier of residents living within 500 meters (yards) radius of the monument, said Dipesh Juneja, superintendent of police in Agra. "This will help the police spot any new entrants or visitors to the area," Juneja said over telephone.

As part of special security arrangements for the monument, the state government has asked the federal civil aviation authorities and India's air force to declare a no-fly zone over a four 2.5-mile radius around the Taj Mahal, said NC Bajpai, Uttar Pradesh's topmost official.

The majestic domed monument was built by the Mogul Emperor Shah Jahan between 1632 and 1654 for his favourite wife, Mumtaz Mahal. It houses their graves and a mosque, as well as several other graves of lesser Mogul royalty.

Nearly 2.5 million tourists visited the Taj Mahal last year, according to official estimates.