Sources: Bin Laden Lieutenant Killed

Nov. 16 -- U.S. intelligence sources have told ABCNEWS they have credible evidence the military chief of the al Qaeda network — a close confidant of Osama bin Laden — was killed in a U.S. airstrike.

The news came as the Pakistan-based Afghan Islamic Press reported the Taliban's supreme spiritual leader, Mullah Mohammed Omar, had agreed to leave the southern city of Kandahar and head for the mountains along with members of his inner circle.

U.S. officials said they are skeptical. "I don't believe it," Rear Adm. John Stufflebeem, a senior officer on themilitary's Joint Staff, told reporters at a Pentagon briefing.

Days after Omar promised a fierce battle for the Afghan city that spawned the Taliban and served as its spiritual stronghold through its five years in power, the AIP reported today that Omar had negotiated a handover of Kandahar to two local mujahideen leaders.

Earlier today, U.S. intelligence sources said they had credible evidence that Mohammed Atef, an Egyptian whose daughter is married to Osama bin Laden's son and was believed to be a senior leader in the al Qaeda chain of command, was killed by a U.S. airstrike in Kabul in the last two days.

Atef was indicted with bin Laden in the bombings of two U.S. Embassies in Africa in 1998 and was believed to have been involved in the Sept. 11 attacks in the United States.

While stopping short of an official confirmation of the reports, U.S. Defense Secretary Donald Rumsfeld told reporters today he had "seen the reports and they seem authoritative."

U.S. Troops in Active Combat in Afghanistan

Earlier today, Rumsfeld said U.S. special forces were in southern Afghanistan and directly engaging al Qaeda members and Taliban troops in their search for bin Laden and Omar.

"They are killing Taliban that won't surrender and al Qaeda that are trying to move from one place to another," Rumsfeld told reporters.

The United States now has at least 300 special operation troops on the ground in Afghanistan and U.S. forces are shifting to a strategy of staging fewer bombing runs while making a stronger effort on the ground to find bin Laden.