Foreign militants and local tribesmen in northern Pakistan resumed fighting near the Afghan border Thursday after a brief break to bury the latest of their 135 dead, security officials said.

Pakistan has cited the fighting as a success in its efforts to get ethnic Pashtun tribes to root out Al Qaeda fighters hiding in the region. But experts say the bloodshed underscored the government's inability to police the region and could unleash a cycle of violence between warring factions.

About 100 foreigners, mostly Uzbeks, and their supporters have died in the bloodshed that began Monday in the South Waziristan region, the three senior officials told The Associated Press.

About 25 tribesmen and 10 civilians caught in the crossfire have been killed, they said. The officials — one from the military and two intelligence agents — spoke on condition of anonymity because they were not authorized to speak to the media.

Hundreds of Central Asian and Arab militants fled to the semiautonomous region after the United States routed the Taliban in Afghanistan in 2001.

Under pressure from Washington, Pakistan sent troops to the border area to wipe out the foreign militants. They have succeeded in busting camps used by al-Qaida but have suffered hundreds of casualties and failed to expel the foreign fighters.

Recently, though, Pakistan has been pressing the tribes to police the region themselves. That has raised concern in Washington that the militants now have freer rein to launch cross-border attacks into Afghanistan on U.S. and NATO forces.

Interior Ministry Aftab Khan Sherpao said Wednesday that the clashes prove that the government's policy of enlisting tribesmen to expel foreign militants was working, and an army spokesman described the local militants as "patriots."

One of the intelligence officials said the killing had resumed after a brief truce on Wednesday to allow both sides to bury their latest casualties. He said the fighting has spread to six villages and towns in South Waziristan, which lies along the Afghan border.

Sherpao said the fighting was still continuing, but provided no further details.