Security has been stepped up in 13 airports in northern India following intelligence inputs that terrorists may attempt to hijack an aircraft.
The inputs suggested that the target could be a plane from or to Kathmandu, highly-placed sources said.
They said Pakistan-based outfit Lashkar-e-Tayiba could be involved.
The Central Industrial Security Force, which is guarding all these airports, stepped up vigil and deployed additional personnel after the Bureau of Civil Aviation Security alerted the paramilitary force about the danger.
The airports where security has been beefed up are Varanasi, Gaya, Guwahati, Amritsar, Bagdogra, Chandigarh, Shimla, Bhuntar, Delhi, Kolkata, Patna and Lucknow.
When contacted, a CISF spokesman confirmed receiving instructions from the Bureau of Civil Aviation Security, but refused to elaborate.
The sources said emergency anti-hijacking measures and multi- layered security arrangements have been put in place at all the 13 airports.
Cabin baggage in flights to specific destinations will be checked and there will be an increase in the profiling of passengers and deployment of security personnel in plainclothes.
Security officials were also carrying out extensive searches around the airports including the parking place.
