PESHAWAR: Hundreds of militants on Friday again besieged a Pakistani area on the Afghan border, shortly after troops claimed to have regained control after fighting killed 34 people, police said.

“Militants have attacked again. There are hundreds of them. They have besieged the area and torched a government school,” regional police chief Qazi Jamilur Rehman told AFP, saying that they had attacked from Afghanistan.

Rehman said reinforcements and helicopter gunships had been moved into the Nusrat Darra area in the northwestern Upper Dir district of troubled Khyber Pakhtunkhwa province in order to quell the attack.

The area is around 10 kilometres from the Shaltalu checkpost which was destroyed by militants in two days of intense fighting, killing 28 policemen and six civilians.

Police said up to 45 militants were also killed in those clashes, which started on Wednesday, but the information could not be confirmed independently as the bodies were not left behind on the battlefield.

Police earlier Friday told AFP that Shaltalu was under control.

“The area is in complete control of our troops. We have started a search operation,” Rehman had told AFP.

Rahim Gul, another police official at the nearby Barawal police station, confirmed the latest attack.

After the first clash, Pakistan Wednesday conveyed “strong concern” to the Afghan ambassador to Islamabad, calling for “stern action” by Afghan and US-led Nato troops to crack down on militants in eastern Afghanistan.

Shaltalu and Nusrat Darra are surrounded by mountains and forest, about six kilometres from the border with Afghanistan's Kunar province.

Upper Dir is part of Pakistan's northwestern Khyber Pakhtunkhwa province and borders the region where the military waged a major offensive to put down a local Taliban insurgency in Lower Dir, Buner and Swat in 2009.

Thousands of Pakistanis have died in bomb attacks over the last four years and thousands more soldiers have been killed fighting home-grown militants.