The U.S. military said a special operations soldier died in an accidental fall during the fighting, some of the fiercest in recent months. The soldier's name was not immediately released.
U.S. warplanes began bombing two suspected Taliban positions in the Chinaran and Larzab mountains of Dai Chupan district in southern Zabul province late Thursday, provincial intelligence chief Khalil Hotak told The Associated Press.
The bombing ended at about 4 a.m., and some 500 local Afghan soldiers moved in on the Taliban fighters, who had taken up fortified positions in a deep mountain gorge and along a stream running through the area, Hotak said at a command center set up in Qalat, about 45 miles south of the fighting.
Hotak described the area as a Taliban stronghold, from which the insurgents direct their operations into the neighboring provinces of Kandahar, Ghazni and Uruzgan. It was impossible to verify his claim independently.
It was impossible to know the exact number of Taliban killed in the bombing and subsequent fighting, but Hotak said the number of fighters killed could be as high as 35. No casualties were reported among the Afghan soldiers.
Four Afghan soldiers were wounded in fighting Thursday.
The U.S. military said a special operations soldier died in a fall suffered during a "night combat assault" in Dai Chupan.
"The injuries were sustained during an accidental fall and were not the result of hostile action," the military said in a statement from Bagram Air Base, north of the capital, Kabul.
Hotak said the largest suspected Taliban base was near a part of the mountain range called Hazar Buz, about four miles from the latest ground fighting. As he spoke, he received calls from commanders at the scene, barking back orders for the ongoing fighting.
"We get information when the Taliban change their positions. Then we give this information to our commanders," he said.
The fighting was still going on by midmorning Friday, Hotak said. His forces believe hundreds of Taliban have taken up positions in the area, with at least 15 hideouts, he said.
Zabul has seen heavy fighting this week. The province's governor, Hafizullah Hashami, said even before the most recent fighting that about 40 Taliban were killed in an ongoing operation to clear out guerrillas hiding in the mountainous area.
Afghan officials say they believe at least two prominent Taliban commanders, Mullah Dadullah and Mullah Shafiq, were leading the fighting in the area.
Hotak also named Mullah Abdul Qahar as one of the commanders leading the Taliban fighters. A native of Zabul, Qahar was a senior Taliban commander in the province before the militia was ousted in late 2001 by a U.S.-led coalition, according to Hotak.
Haji Granai, an Afghan military commander, said at least two U.S. bombers and two helicopters helped in the operation, and Hotak said 20 American troops and 12 military vehicles were on the ground to aid the Afghan forces.
Two fighters arrested in the area two days ago told investigators they were recruited by the Taliban and fighters loyal to Gulbuddin Hekmatyar. They said they received $650 from the two groups, Hotak said.
Hekmatyar, a former prime minister who has since fallen into disfavor, so far has eluded U.S. efforts to arrest or kill him. The renegade warlord has issued calls for a jihad, or holy war, against foreign troops in Afghanistan.
In other fighting, a group of suspected Taliban attacked an Afghan checkpoint in Spinboldak, 130 miles southwest of the Zabul province fighting.
Three Afghan soldiers were killed in Thursday's attack, said Fazluddin Agha, district police chief of Spinboldak. Two Taliban fighters were wounded in the exchange of gunfire, he said.