India has heightened security at all major airports after central intelligence agencies warned of a possible terrorist hijack of an Air India flight between New Delhi and Kabul.
Officials said that they had received specific input on Saturday, which spoke of a possible hijack attempt similar to a 1999 incident when Indian Airlines flight IC814 was hijacked from Indian airspace and flown to Kandahar, Afghanistan.
The Hindustan Times quoted sources as saying that there a possibility of Pakistan's spy agency, ISI, targeting Air India flights between India and Afghanistan, especially those carrying Indian diplomats.
According to an Indian Express report, stringent and thorough passenger and baggage checks have been issued at major airports, such as Indira Gandhi International Airport in Delhi. Airport staff are also going through strict checks.
Post-boarding screening of cabin baggage is also being carried out.
Sky marshals trained at preventing hijack attempts have been deployed on Air India flights, while other international airports have been put on alert.
The Hindustan Times quoted an Air India official as saying: "We are conducting a second security check of passengers just before they enter the aircraft. Once the passengers are seated in the plane, our crew has been instructed to get the cabin baggage verified with the passengers again.
"Also, at the time of issuing the boarding pass a detailed examination of the passport is being done."
The Air India control room in Kolkata had received a hoax call on Saturday from an unidentified person, who said the Kolkata-Kabul flight would be hijacked.