NATO: 4 dead in Afghan military base shooting

KABUL, Afghanistan — Two American civilians and two Afghan soldiers were killed in a shooting on a northern Afghan military base Tuesday, NATO said.
An Afghan soldier who trained others at the base outside Mazar-e-Sharif started shooting during a weapons exercise, the international military coalition said in a statement.
The shooter was one of those killed, and it was not immediately clear if he had been targeting someone or if bullets had gone astray. It also was not clear how many people fired weapons.