Indian airports on terror alert

Security was tightened at southern Indian airports

Key domestic and international airports in India have been put on alert following an anonymous threat of attacks, officials say.

Security has been tightened at five airports in southern India following the receipt of a letter threatening an al-Qaeda attack on one of them.

The airports on alert are Madras (Chennai), Trichy, Coimbatore, Kochi and Trivandrum.

In August, the US had warned of possible terror attacks in India.

Officials said that the chief of the Trichy airport received an anonymous letter on Tuesday evening from someone claiming to be a spokesman for al-Qaeda and threatening an attack on the Chennai airport.

One report said that the letter carried out the threat of car bomb attacks at the airport.

"Although, we have received similar threats in the past, this time as the letter particularly mentioned car bombs we could not take it lightly," Chennai airport director S Sreekumar was quoted telling reporters by the AFP news agency.