American B-52s have been bombing caves in mountains east of Jalalabad as they hunt for Osama bin Laden.
The jets dropped 250 and 500lb bombs at Tora Bora.
Local tribesmen believe bin Laden might be holed up inside caves in the forested area.
Dozens of planes flew missions overnight after anti-Taliban forces used tanks and mortars to attack al-Qaida guerrillas loyal to bin Laden.
Doctors at Jalalabad's main hospital say an officer, from the eastern Shura anti-Taliban grouping, and five of his men were wounded in an al-Qaida ambush. As many as 1,500 tribal fighters pushed down a valley towards the fortified complex.
Pentagon spokesman Rear Adm John Stufflebeem says US special forces are in the area helping direct air strikes and are gathering intelligence. He says Afghan fighters have already entered some caves in the hunt for al-Qaida members.
Commanders in the Northern Alliance suggest it is more likely that bin Laden is hiding somewhere around Kandahar, which the Taliban says it will defend to the death.
Meanwhile US Marines, who have been building up a base in the desert outside Kandahar for days, have now moved to offensive operations for the first time.
US officials say they are helping to cut off roads and communications into the city and cutting off possible Taliban escape routes.
Major James Parrington, an operations officer at the base, says Marine reconnaissance units are already identifying key pieces of terrain to be used in sealing off the city.