A pair of suicide bombers attacked an Afghan intelligence services compound in the southern city of Kandahar on Monday, but security forces held them off, a local official said.
Afghan forces fired on the attackers, leading to a 20-minute gun battle in which at least one of the suicide bombers was wounded, said the head of Kandahar's provincial council, Ahmed Wali Karzai.
He said the wounded bomber detonated his explosives, but there was no major damage to the compound.
The second bomber was killed, Karzai said.
Two intelligence agents and a teacher at a nearby school were injured in the attack. It was not immediately clear whether they were injured by the explosives or were caught in the crossfire.
The attacks came amid a day of turmoil in Kandahar, the largest city in southern Afghanistan, where Afghan and international forces are planning a major assault to drive out Taliban insurgents.
Residents blocked a major highway with burning tires and denounced the United States after international troops fired on a bus carrying Afghan civilians early Monday, killing four people.