US bombs rain down and tribal attack launched on al-Qaida

US airstrikes have intensified dramatically and Afghan tribal fighters have launched a new ground assault against trapped al-Qaida forces.

The action follows claims that key terrorist leaders, including Osama bin Laden, have fled to Pakistan.

Front-line tribal commanders of the eastern alliance say they had abandoned a plan for al-Qaida fighters to disarm and surrender.

One tribal unit has advanced and captured a key al-Qaida position. Tribal officers say their forces are determined to crush the enemy, most of them Arabs and other foreign Muslim fighters.

"The al-Qaida forces are about to be finished," said one commander, who identified himself only as Hamid. "They don't have any more food or ammunition."

Hamid says the latest assault was ordered after it became clear that senior al-Qaida chiefs had fled and had left the Tora Bora area and abandoned their rank-and-file troops.

He says the fleeing leaders might be trying to cross the Pakistan border, just a few miles south across the White Mountain range.

Pakistan has said that it has reinforced the border to prevent al-Qaida incursions. It is also unclear why the Afghans think major al-Qaida figures have taken part in the defence of the Tora Bora area.