All airports in India were today advised to adopt 'heightened security measures' following an intelligence tip-off that the United Liberation Front of Assam (Ulfa) is planning to hijack an aircraft.

The Bureau of Civil Aviation (BCAS) has alerted airports across the North-east, saying Ulfa is more likely to attempt to hijack a plane at some airport in the N-E to demand the release of its jailed founding members.

A red alert has been sounded in airports across the country, sources in the Union civil aviation ministry confirmed.

Paramilitary forces have been deployed in all airports in the N-E and Army units near the airports have been asked to stand by.

Emergency anti-hijacking measures and multi-layered security arrangements have been put in place at most of the crucial N-E airports.

This is the third such warning against the Ulfa from the Bureau of Civil Aviation. Two earlier warnings were issued in 2004.