Hundreds of Taliban militants attacked a checkpost in a Pakistani tribal area bordering Afghanistan, sparking fierce clashes in which 10 troops and 25 rebels were killed, officials said yesterday.

Helicopter gunships pounded insurgent positions during the fighting, which erupted when paramilitary forces reoccupied a security post in the Bajaur tribal zone, which they had abandoned several months earlier.

Bajaur is a known haven for Taliban and al-Qaeda militants, against whom Washington has urged Pakistan's fledgling government to crack down.

"The fighting is intense and ongoing," a top security official told AFP. "Up to 25 militants were killed and at least 10 Frontier Corps soldiers have also been martyred. Some are critically wounded."

Officials said that a contingent of troops moved into the Loisam area, around 15 kilometres (nine miles) from Khar, the main town in

Bajaur, late Wednesday to control militant movements between several districts.

An officer from the paramilitary Frontier Corps said 300-400 mili-tants , backed by local sympathisers, participated in the attack. They were mostly armed with AK-47 assault rifles, rocket launchers and grenades, he said.

"The firing continued the whole night, this morning reinforcements were sent. One vehicle was hit by an improvised explosive device on its way to the post and the convoy was then attacked by Taliban militants," thcofficial said.

One soldier was killed in the bomb blast and the rest were killed in the fighting, they said.

The Frontier Corps official would only confirm the deaths of five soldiers but said that many were critically wounded and had been taken to hospital outside his area.

A Taliban spokesman, Maulvi Omar, said militants killed 18 soldiers while only two Taliban fighters died and claimed that

fighters from the hardline movement had surrounded the post.

"The fighting will continue until the troops are withdrawn from Loisarn. We will respond with full might," Omar said in a telephone call to local reporters from an unknown location.

Helicopters pounded suspected militant positions onThursday and fresh shelling resumed in the morning, security officials said. Markets and offices were closed in Khar and traffic was thin.

Loisam lies on the strategically important road leading towards the main northwestern city of Peshawar.

Taliban militants had exercised complete control over Loisam since the withdrawal of troops earlier this year, using it as their main base for operations in the area, residents said.

A few weeks ago Taliban militants seized several government schools and converted them into Islamic seminaries, people living in theareasaid.