Federal Bureau of Investigation, American Intelligence agency, has alerted Indian government of a possible terror strike at across the country and possible plane highjack.

A security cordon was immediately placed around the Indira Gandhi International (IGI) airport at Delhi and all vehicles entering were checked. Vehicles were not allowed to stop in front of the terminals for more than a couple of minutes. Even airport employees were stopped for identity verification. The baggage of airline employees was also checked.

A security official said the Bureau of Civil Aviation Security (BCAS) had issued an advisory to the Central Industrial Security Force (CISF) to put in place more stringent security measures at all airports. The BCAS is the regulatory authority for civil aviation security in India, while the CISF manages security at airports across the country.

The alert from the FBI was received on Saturday evening. According to reports, an internet centre in the US received an e-mail that US-bound flights from India might be hijacked.

He said the BCAS has advised the CISF to increase security checks which would include "profiling passengers, increased checks of cabin baggages, and apron security of US-bound flights of all airlines".

Anti-sabotage and anti-hijacking measures are being put in place at all airports and marshals have been deployed at airports. Airlines have asked passengers bound for the US to report four hours before scheduled departure time for boarding and security-check procedures.

S.R. Mehra, commissioner of security, BCAS, that no racial and ethnic profiling of passengers would be undertaken. "Profiling in this context means a well-calibrated scientific effort to assess the behaviour of any passenger that may require further investigation", he added.