U.S. and Afghan forces have been fighting running gun battles with insurgents in the eastern city of Khost, after teams of suicide bombers and militants attacked government buildings there.
Officials say at least 20 people were killed in the fighting, and three U.S. troops were wounded.
U.S. and Afghan troops freed 20 hostages taken by the insurgents.
Officials describe the situation as chaotic. A Taliban spokesman claimed that 30 suicide bombers were involved.
The Afghan Interior Ministry says the attacks began when a suicide car bomb exploded outside the governor's compound, where U.S. troops were meeting with the provincial police chief.
A team of five suicide bombers then tried to attack the police headquarters nearby. They were turned back by security forces, but entered a neighboring building where three detonated their explosives.
Militant gunmen fired on an American quick-reaction force as they sped to the scene.