Updated

A U.S. warplane strafed buildings in southeast Afghanistan after troops searching for al-Qaida and Taliban fighters came under fire, an official said Tuesday. Elsewhere, American soldiers killed two men who shot at them.

The two separate incidents took place Monday, U.S. spokesman Col. Roger King said. No Americans were injured in either shooting, he said.

In the morning, a special forces patrol was fired on near the southern town of Tarin Kowt, about 70 miles north of Kandahar, King said. The patrol shot back and killed the two attackers, he said.

The identity of the attackers was not yet known. Remnants of the Taliban militia that once ruled Afghanistan are thought to be active in the region north of Kandahar, but the area is also rife with warlords with private militias.

In southeastern Afghanistan, a team of some 20 U.S. special forces troops and 40 allied Afghan fighters came under small arms fire Monday evening from a complex of buildings outside the town of Shkin, near the Pakistani border, King said.

The Americans fired back and called in an AC-130 gunship, which strafed the buildings. The troops waited until daylight Tuesday and began searching the buildings. It was not yet known if any of the attackers were killed, King said.

About 1,000 U.S. special forces troops have been searching the region near the border for al-Qaida or Taliban members infiltrating from Pakistan — but the search has found almost no fighters in recent weeks.