A new offensive is under way in eastern Afghanistan to try to dislodge al-Qaeda fighters from positions in the hills above the Tora Bora cave complex.

Throughout Thursday, United States aircraft bombed the al-Qaeda positions while anti-Taleban ground forces launched their own attacks.

All day, a sound like thunder rumbled down the valleys above Tora Bora: each explosion followed a flash of light and a plume of dust and ash rising like a mushroom cloud on the high ridges where the al-Qaeda fighters have their positions.

On the ground, too, men from the anti-Taleban eastern Shura headed up the valley by the car load, armed with Kalashnikovs and rocket-launchers.

The offensive started after commanders gave up trying to negotiate a surrender deal.

'No stopping'

They had asked for 22 senior al-Qaeda leaders to be handed over.

Hazrat Ali is the commander leading the new assault. He's hopeful the attack might take just one day to complete.

"Our people are just advancing - there's no stopping of our forces from the Taleban or from al-Qaeda," said Mr Ali.

"Well, I am hopeful that by tomorrow everything will be finished."

In the mid-afternoon, snow fell on the high slopes where the al-Qaeda fighters have been dug in.

Another local commander said the ground forces had met stiff resistance later in the day and the al-Qaeda men had retreated to a forest perched on the hillside.

He also said he believed al-Qaeda's leaders might have fled the area.

High mountain passes lead to Pakistan but are blocked by snow.

As the darkness drew in there was no let-up in the attacks.