US warplanes bombed behind front–line Taliban positions near Kabul in an effort to weaken defenses and allow opposition troops to advance toward the capital.
Witnesses said they did not hear any anti–aircraft fire from Taliban fighters, who have periodically tried to shoot down U.S. jets since bombing began more than five weeks ago.
However, there were no signs that the Afghan opposition, a loose coalition of fighters dominated by ethnic minority Tajiks and Uzbeks, was on the offensive near Kabul.
But the opposition has claimed victories on another main front, near the strategic northern city of Mazar–e–Sharif.
Backed by heavy U.S. bombing, the opposition northern alliance said Tuesday it captured several areas to the south of the city. Still, opposition forces remain at least 60 kilometers (40 miles) south of the city with winter closing in.
To the north of Kabul, witnesses said U.S. jets dropped dozens of bombs late Tuesday and two bombs early Wednesday behind the front line, about 25 miles (40 kilometers) north of the capital. Some explosions were followed by up to 30 smaller detonations.
The Taliban's Bakhtar News Agency said bombs north of Kabul and in the eastern city of Jalalabad killed at least 10 people and injured 19. The report could not be independently confirmed, and the Pentagon has denied Taliban claims of widespread civilian casualties.
At the Pentagon, Defense Secretary Donald Rumsfeld said Tuesday that an assessment of the opposition claims of gains outside Mazar–e–Sharif would have to wait until the "dust settled."
But after seesawing battles south of Mazar–e–Sharif in recent weeks, the opposition said intense strikes by American planes helped open the way for Tuesday's advance. The alliance had complained earlier that U.S. bombing was not heavy enough.
Retaking the city, which the Taliban captured from the opposition in 1998, would greatly damage the Islamic militia's power in the north.
Rumsfeld said U.S. military planners hope that American help to the opposition alliance – including weapons and ammunition – will unite its factions so "that we will see more success" on the ground.
The Pentagon has said small numbers of American special forces teams are working with northern alliance forces to train and equip them, provide them with additional ammunition and weaponry, and identify targets for U.S. strike aircraft.
The Pentagon also intends to start delivering cold–weather clothing to the northern alliance, officials say.
President George W. Bush launched airstrikes against Afghanistan on Oct. 7 after the ruling Taliban militia refused to hand over Osama bin Laden for his alleged role in the Sept. 11 terrorist attacks against the World Trade Center and the Pentagon.
On Tuesday, Bush pledged "to keep relentless military pressure" on bin Laden and the Taliban, saying it is essential to keep terrorists from acquiring nuclear, chemical and biological weapons.
Rumsfeld said the United States extracted Hamid Karzai, a southern opposition leader, from Afghanistan over the weekend. Taliban forces had been chasing Karzai as he tried to rally support among ethnic Pashtun tribes for an alternative to the Taliban.
The United States wants the Afghan opposition to make significant gains ahead of winter. Fighting traditionally tapers off then because snow closes roads and hampers the resupply of troops.