Both sides used mortars, heavy guns and rocket-propelled grenades in battles overnight in South Waziristan, following the collapse of a week-long ceasefire. Intermittent firing continued on Friday morning.

Violence first erupted in the region on March 19 when a Taleban commander-turned-government supporter ordered Uzbek and Chechen militants led by wanted rebel Tahir Yuldashev to disarm, leaving 160 people dead last week.

Tribesmen on Thursday seized control of a school which the Uzbeks were using as their base in Ghawakha, a town near the regional capital Wana. ‘Seven Uzbeks were killed in the building,’ a security official said.

Another official said three tribal fighters were also killed and six wounded in the fighting. Three Uzbeks were wounded and four captured in different incidents.

Foreign militants also shot dead a local man who was travelling in the area on his motorbike, residents said.

The government says the latest developments reflect the success of its policy to encourage local tribesmen to expel foreign Al Qaeda militants, instead of costly and politically damaging army operations.

Thousands of Al Qaeda and Taleban militants fled into Pakistan’s tribal areas after the fall of the fundamentalist Taleban regime in Afghanistan in late 2001.

Yuldashev, the Uzbek leader, was formerly a close confidant of Al Qaeda leader Osama bin Laden, officials say.

The latest clashes were concentrated in the mountainous Azam Warsak, Shen Warsak and Kalusha areas near the Afghan border. Residents say between 300 and 500 Uzbeks and Chechens are holed up in the area.

The Uzbeks were effectively under seige in the mountainous terrain as all roads leading to the troubled towns were being controlled by tribal commander Mullah Nazir, whose men are said to number around 1,500, they said.

A tribal leader, Haji Sharif, late Thursday ruled out any negotiations.

‘We gave them shelter under our traditional Pashtun hospitality but they misused it and killed our people including tribal leaders,’  he said.

‘We advised them to change their behaviour but they did not listen. Now we cannot tolerate them on our soil.’