Bagram, Afghanistan ? Five American soldiers were injured and two Afghan militiamen were killed Saturday in a 4 1/2-hour gun battle in eastern Afghanistan during a search for Taliban and al-Qaida fighters believed holed up in the lawless region.

At least three of those who opened fire on the U.S. and Afghan troops from a mud-brick compound also were killed, said Col. Roger King, military spokesman at Bagram, the main U.S. base in Afghanistan. One attacker was wounded and is now in U.S. custody.

It was the fifth time U.S. forces have been attacked since hostility against them rose sharply after a U.S. air strike July 1 that Afghan officials say killed 25 people at a village wedding party.

The wounded soldiers were flown to Bagram. Four of them, wounded early in the attack, had injuries that were not life-threatening. The condition of the fifth, wounded late in the gunfight, was not immediately known.

The Khost region, about 90 miles southeast of Kabul, the capital, is regarded as one of the most insecure areas of Afghanistan, and forces of the U.S.-led coalition have repeatedly conducted operations there aimed at flushing out holdouts of the Taliban and al-Qaida.

It is exceptionally difficult terrain, where soldiers clamber among arid, steep mountains that provide an array of hiding places for fugitives and perches for snipers. Mud houses cling to slopes above the passable byways.

King said about 50 U.S. soldiers and allied Afghan militia were trying to confirm intelligence about an enemy operative in the area when they came under small-arms fire about 1 p.m.

Special Forces and conventional troops were flown to the fight after the ambush, putting a total of about 100 troops on the ground, King said.

The injured soldiers’ names were not released pending notification of relatives.

King said a team was continuing reconnaissance in the area.

“It suggests that we’re facing a committed enemy,” King said. “It suggests what we’ve tried to say all along, that this is not a quick fix, it’s not going to be over tomorrow. It will be a long drawn-out campaign. …

“We are doing a lot of our operations in there because of its proximity to the border, because of the history of the area and its connection to the people we are looking for,” King said. “Those things work together to make the border region a focal point.”

Afghan anger against the United States has risen since the July 1 air strike that Afghans say killed 48 people 25 of them celebrating a wedding and wounded 117 in Uruzgan.