Islamabad- Pakistani security forces launched operations against the Taliban in an area captured last week by militants, a military spokesman said Tuesday. Meanwhile, troops finished a similar offensive in another northern district near Islamabad, killing up to 75 rebels, the military said.

Jet planes and helicopter gunships targeted militant positions in the mountains surrounding the Buner Valley in the Buner district, 100 kilometres north-west of Islamabad, Major General Athar Abbas told reporters in the garrison city of Rawalpindi, adjacent to the capital.

"The overall objectives of the operation are to eliminate and expel militants from Buner," Abbas said.

He said the operation was mainly conducted by the paramilitary Frontier Corps, (FC) but regular army troops were assisting them.

The United States welcomed the assault after expressing concerns that the Pakistani government has not been acting swiftly enough against the militants.

"We are very much encouraging of those efforts and stand ready to help them in any which way that we could," Pentagon spokesman Geoff Morrell said.

About 300 heavily armed militants infiltrated Buner, taking over state buildings and setting up checkpoints across the district, a move that was widely received with concern, given the area's proximity to the capital of the nuclear-armed country.

The development followed last month's peace agreements that the government signed with militants in the nearby Swat Valley to end a 16-month conflict in exchange for the enforcement of Islamic law there. But the accord encouraged the militants, who expanded their influence to the neighbouring districts of Lower Dir and Buner.

With some initial hesitation, the government on Sunday started limited action in Lower Dir.

"The Dir operation has been completed," Abbas said. "Seventy to 75 militants have been killed, and many of them have been flushed out of the area. Ten security personnel have been martyred."

He acknowledged, however, that some pockets of resistance remained in the area.(dpa)