An anonymous letter received at the Tiruchy airport warning of bomb threat by ‘Al Qaeda terrorists’ to airports in Tamil Nadu and Kerala has sent airport officials and state police into a tizzy with security being tightened at Chennai, Tiruchy, Madurai, Coimbatore and Thiruvananthapuram airports.

The hand written letter in Tamil, titled ‘Allah Osama,’ found by the CISF at the Tiruchy airport this morning warned that ‘Al Qaeda terrorists’ would set off modern explosive devices at airports in Chennai, Tiruchy, Madurai and Coimbatore and “some airports in Kerala,’’ said P Kandasamy, Tiruchy DIG.

In Chennai, a high-level meeting was convened by the state IG (Intelligence) Subramanyam and Chennai Airport Director Dinesh Kumar. “The meeting assessed the threat perception and decided to take extra security measures at all these airports,’’ Kumar said, adding that the threat letter “would be viewed seriously as safety of passengers and airport operations were of prime importance.’’

As the letter talked about “car bombs’’ as well, all vehicles entering the airport would also be screened, officials said, adding that “all standard security procedures would be invoked.’’