The security forces in Tamil Nadu was put to a high alert after the Adyar police station received a letter threatning attack on vital installations. The writer has not specified the date or time of the attack. The letter mentions  the Tamil Nadu Police Academy, Chennai Airport, Officers Training Academy and the American Embassy (U.S. Consulate) among others as its targets and challenges the force to prevent it. However, sudden security measures were taken to protect all vulnerable parts of the city from any attacks. The authorities are still not clear with the genuinity of the letter. “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,” , said Commissioner of Police T Rajendran.