Tribal fighters celebrated the capture of the bunkers by firing tracer rounds in the air that illuminated the sky over Wana, the main town in the South Waziristan region bordering Afghanistan, residents said.

The latest deaths bring the toll from fierce clashes in troubled South Waziristan, which erupted between the two sides on March 19, to around 270, with about 70 of those fatalities in the past three days.

The government says the tribesmen are trying to drive out Uzbek and Chechen militants because the foreigners have ties to al-Qaeda and are involved in attacks on US and Nato forces in Afghanistan.

In the major assault the tribesmen overran several bunkers held by Central Asian rebels, which were originally built by the Pakistani army but vacated in 2005 after tribesmen signed a peace deal with the government.

"They were very strong bunkers and Uzbek fighters were well entrenched there. But the tribesmen managed to flush them out," local administration chief Mohammad Hassanzada told AFP.

"Some 20 bodies were found lying there before dawn and more casualties were feared as the fighting continued throughout the night," a security official said. Sporadic gunfire continued on Friday morning.

Residents said the dead in the clashes overnight included seven tribesmen, one of whom was the driver of their main commander, Mullah Nazir, the former local Taliban leader.

The clashes broke out last month when Nazir ordered the foreign militants led by Uzbek extremist Tahir Yuldashev, a one-time confidant of Osama bin Laden, to disarm or leave the area.

Thousands of Arab and Central Asian militants were given shelter by Pakistani tribesmen after fleeing Afghanistan when US-led forces toppled the Taliban regime in late 2001, but the two sides have now fallen out violently.

A ceasefire broke down late last month and tribal elders banged war drums on Wednesday to gather a force of around 1,000 fighters to mount a final push against the foreigners.

The tribesmen at a meeting on Thursday demanded help from military helicopters and heavy weapons from the government to capture the mountainous bunkers.

"The government has been telling us to expel the foreigners. It should help us as we are flushing them out now," a tribal elder named Sher Jan told the jirga or council of tribal elders in Wana.

Local officials said so far the government had not intervened. The Pakistani military said it had not been involved in the fighting, although the government supports the tribesmen's actions.

Uzbek fighters later Thursday torched the house of Sher Jan, in Dana village, 10 kilometres (six miles) west of Wana. Jan has been at the forefront of the efforts to bring the tribal force together.

A gunbattle then erupted in which Jan's brother was killed and his son and a nephew were wounded, security officials said.