Afghan officials say a US soldier has shot and killed an Afghan guard at a base in the country\'s north. Officials allege the Friday shooting occurred because the American thought his Afghan colleague was about to attack him. Saripul province Police Chief Sayed Jahangir said on Sunday that the Afghan guard and the American soldier had been arguing at the gate of a US base. Jahangir says the guard did not raise his weapon but the American thought he was about to do so and fired. US military spokesman Lt. Col. Jimmie Cummings says US forces were \"aware of an incident in northern Afghanistan\" and were investigating. He declined to provide further details.