The Chhatrapati Shivaji International Airport (CSIA) in Mumbai has been put on high alert following a specific threat of possible bomb explosion or suicide attack on an Air India flight from Mumbai.

The terror threat was received at Kolkata, about the possible targeting of an AI flight on the Mumbai-Kochi sector on Saturday and on an Ahmedabad-Mumbai flight onFriday.

The security at concerned flights and other airports havealso been beefed up, said the security officials.

The aviation officials said that the Director of Airports Authority of India, Kolkata, had received an anonymous call last night stating that AI flights on the Ahmedabad-Mumbai and Mumbai-Kochi sector will be 'sabotaged'. While another version is that an email regarding terror threat was received by the airport director.

A Bomb Detection and Disposal Squad, Quick Response team, CISF and police are keeping a constant vigil at the airports, following the alert. The Bureau of Civil Aviation Security (BCAS), Central Industrial Security Force (CISF), intelligence agencies and local police are keeping constant vigilance over the situation, said an airport official from CSIA.