Afghan soldiers conducting a sweep in a mountain area south of the capital exchanged fierce fire with suspected Taliban (search) rebels, killing eight and capturing 16 in some of the heaviest fighting in months, officials said Tuesday.

Mohammed Zahir Azimi (search), a spokesman for the Afghan defense ministry, said U.S. warplanes joined in the battle Monday in the mountains of southern Zabul province. A spokesman in the Zabul governor's office, Ali Khail, said Chechens and Arabs were among those killed and captured.

Khail also said the U.S. military provided air support for the Afghan forces, and that some of the captured militants were turned over to U.S. custody.

A spokeswoman for the American military, Lt. Cindy Moore (search), said that as of Monday evening she had received no reports of fighting in the area involving U.S. forces. The region is extremely remote, and there was no way to immediately reconcile the two stories.

Khail also said a local Taliban commander named Mullah Abdullah may have been among those killed, but that there was no confirmation of his death.

In another incident, suspected Taliban rebels ambushed a patrol of Afghan soldiers in southwestern Oruzgan province, sparking a one-hour firefight, Gov. Jan Mohammed Khan told The Associated Press.

Two Taliban were killed in the fighting Sunday, and Afghan soldiers arrested a regional Taliban commander named Mullah Allah Noor. The other militants escaped into the mountains.

Meanwhile, the U.S. military said Monday that one of its CH-47 helicopters operating in the south made a "precautionary landing" near Kandahar after developing a mechanical problem. Moore said there were no injuries in the incident, which occurred early Sunday, and that the helicopter was repaired on site.

A rapid reaction force was sent out to bring the soldiers on board safely back to base. Moore had no details on how many soldiers were on the helicopter when it was forced to land.