Bagram, Afghanistan ? Four gunmen on motorcycles ambushed a U.S. military reconnaissance patrol in southern Afghanistan on Saturday, killing two U.S. soldiers, officials said. Another American and three Afghan soldiers were wounded.

Meanwhile, U.S. special operations soldiers backed by air support joined about 1,000 Afghan troops to battle about 100 Taliban fighters in southern Uruzgan province, the U.S. military said. At least 15 Taliban fighters were reported killed.

The ambush attack was the first fatal encounter for U.S. forces in this country since December, but came just two days after a Red Cross worker was killed in southern Afghanistan in what could signal a resurgence of activity by holdout fighters of the former Taliban regime.

Taliban loyalists

Afghan authorities Saturday accused Taliban fugitives and their al-Qaida allies, as well as forces loyal to renegade rebel commander Gulbuddin Hekmatyar, of ambushing the convoy.

In recent interviews with The Associated Press, Taliban loyalists hiding in neighboring Pakistan said training camps were established in the Afghan mountains and anti-American forces had united. They warned of stepped-up attacks once the war in Iraq began.

The ambush came as a four-vehicle convoy carried out a reconnaissance mission near Geresk. One special forces soldier and an airman were killed and another special forces trooper and the three Afghan soldiers were wounded, the military said in a statement from Bagram Air Base, the headquarters of U.S. forces north of the capital, Kabul.

The Pentagon identified one of the slain Americans as Staff Sgt. Jacob L. Frazier, 24, of St. Charles, Ill., who was assigned to the 169th Air Support Operations Squadron, 182nd Airlift Wing. The other casualties were not immediately named.

Geresk is in Helmand province, about 70 miles west of Kandahar.

U.S. response

Army spokesman Col. Roger King said there were less than 20 people in the convoy.

“They drove into a kill zone,” King told The Associated Press.

The convoy sped out of the area after the Americans were shot and a gunfight ensued, King said.

There likely will be a response from the U.S. military, which recently finished an antiterror sweep known as Operation Viper in the area.

“We’ll probably make attempts to find out who did the ambushing,” King said, without elaborating.

Saturday’s deaths bring to 18 the number of U.S. forces killed in combat in Afghanistan.

Dad Mohammed Khan, the intelligence chief of Helmand, told AP the U.S. soldiers were inspecting a school and hospital built with American funding when they were ambushed by four men riding two motorcycles. The gunmen escaped.