BAGRAM, Afghanistan -- After weeks of no reported combat with al-Qaida or Taliban fighters, American-led forces clashed with "terrorists" and several of them were believed killed, the U.S. command said Sunday.

Rockets were also fired at a U.S.-controlled airstrip in southeastern Afghanistan, stark reminders that this country's struggle to overcome 23 years of war is far from over.

There were no casualties among U.S. special forces or their Afghan allies in the Saturday skirmish, which erupted after a joint patrol came under fire, U.S. military spokesman Maj. Bryan Hilferty said. Hilferty said troops called in air support from an AC-130 airborne gunship but would not say where the clash took place.

Hilferty said the troops could not confirm the death toll among the attackers but said the patrol believed it had "killed several terrorists" because "the AC-130 saw them, fired, and then didn't see them any more."

The second attack took place outside Khost, a southeastern city near the Pakistani border. Khost is believed to be one of the last Taliban and al-Qaida strongholds in Afghanistan since the Islamic militia was toppled from power in December.

Accounts of what happened there varied. A local leader contacted by satellite phone said unidentified attackers fired three rockets at the airstrip around midnight. A building was hit, injuring three Afghans, according to Fazal Mir.

Failed rocket attack

In Kabul, however, Tribal Affairs Minister Amunalah Zadran said two BM-12 missiles exploded about four miles from the airport and no one was hurt.

Maj. David Rasmussen, a U.S. Army operations officer, said people at the scene heard what sounded like rockets or mortars hit the southwest end of the field early Sunday, but said no buildings were hit and there were no injuries. No American troops were at the base at the time, he said.

The attacks underscored the challenges facing interim Prime Minister Hamid Karzai's administration as it prepares for the return of the country's exiled king to convene a June loya jirga, or grand council, to select a new government. But there were also shaky signs of peace Sunday.

Fighting west of Kabul ceased as an emissary was sent from the capital to broker a truce between rival commanders engaged in a two-day turf battle.