Security forces were put on high alert in Chennai and its suburbs since late on Thursday night following a threat letter that warned of attack on vital installations.

Though the letter received at the Adyar police station here did not specify any date or time of the attack, it named the Tamil Nadu Police Academy, Chennai Airport, Officers Training Academy and the American Embassy (U.S. Consulate) among others as its targets and challenged the police to avert the sabotage if they could, police sources said.

The Chennai Police enhanced surveillance and manpower deployment at vulnerable places as part of the ‘Standard Operating Procedure’.

“It could be a prank call…but we are not taking any chances. Anti-sabotage checks are being conducted at vantage points and police presence has been stepped-up in areas of public gathering,” Commissioner of Police T. Rajendran said on Friday.

Since the Chennai Airport was also cited as a target, the Central Industrial Security Force was alerted. “Unlike the usual hoax calls, this letter talks of RDX explosives, rocket launchers, grenade attacks and shootouts. There is also a mention that the entire planning was being done at a place in Kotturpuram in Chennai.”

Mr. Rajendran said patrolling and vehicle checks had been intensified in the city. “No specific threat has been perceived by the intelligence agencies. We have formed a special team to investigate the source of the letter which also states that the details of the attack would be informed later.”

According to a source in the intelligence, the letter even listed T. Nagar, Ritchie Street and Marina Beach as targets. It warned of an RDX explosion at the Chennai Central railway station.

‘No panic situation’

Director General of Police K.P. Jain said there was no panic situation and instructions were given to the agencies concerned to carry out mandatory checks. “Such letters keep coming and we never take anything lightly,” he added.

Additional Director General of Police (Law and Order) K. Radhakrishnan said the Railway Police were told to mount surveillance at the Central and Egmore railway stations in Chennai.

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