Jammu, Aug 5 (IANS): Two troopers were killed when militants on Wednesday ambushed a BSF convoy on the Jammu-Srinagar highway in Udhampur -- in the first such attack on the heavily-guarded road in 15 long years. After one of them was killed, the surviving militants took three villagers hostage.

The heavily-armed rebels attacked a Border Security Force convoy at Narsu Nallah, 65 km from here between Udhampur and Chenani towns.

A senior police officer told IANS that two BSF troopers and a militant were killed and 11 troopers were injured when a fierce gunfight broke out. The injured were rushed to a hospital.

In 2000, militants had attacked a bridge guarded by the BSF in Ramban district on the Jammu-Srinagar highway. No casualty or damage had occurred then.

Soon after Wednesday's ambush, the militants -- who clearly knew the area well but whose precise numbers were not known -- raced towards the mountains and entered Chirdi village some 15 km away.

Security forces quickly encircled the village and began a hunt for the killers.

A senior police officer told IANS: "After the attack on the BSF convoy, the militants who escaped entered a house in Chirdi village (in Udhampur district).

"The village has been surrounded by security forces who are now closing in on the house where militants have taken three people hostage."

Former Jammu and Kashmir chief minister Omar Abdullah said the attack on that stretch of the national highway had happened after "a very long time. Worrying development because area was militant free".

Congress vice president Rahul Gandhi called the attack "extremely worrying". "Days after the Gurdaspur attack, the militant attack on a BSF convoy in Udhampur is extremely worrying."