India declared a high security alert at several of its airports on Thursday following the discovery of an anonymous letter threatening car bomb attacks by the al Qaeda terror network, officials told AFP.
A senior Home Ministry official said a security advisory had been sent to 20 domestic and international airports, after the threatening letter was discovered in a rubbish bin in a southern Indian airport.
A spokesman for the Central Industrial Security Force, which guards civilian airports, said some six airports -- mostly in the south of the country -- had been placed in a state of "high alert".