The clash occurred when Afghan security forces were reconstructing an outpost that was damaged in a blast few days ago.
Afghan officials blamed the Taliban for the attack.
Since 2001 when the United States invaded Afghanistan, over 100,000 people have been killed in the war, including more than 4,000 ISAF soldiers and civilian contractors, more than 62,000 Afghan national security forces, 31,000 civilians and even more Taliban members.