An Afghan soldier opened fire on American soldiers on Saturday, injuring at least seven, the USA military said.
Abdul Qahar Araam, spokesman for the Afghan army's 209th Corps, announced earlier that an Afghan soldier had shot and killed four USA soldiers inside the base.
The shootout at Camp Shaheen near northern Mazar-i-Sharif city is the second "green-on-blue" attack - where Afghan soldiers turn their weapons on worldwide forces assisting them - reported this week.
For the second time in a week, a man in an Afghan army uniform opened fire on USA service members at a base in Afghanistan.
The attacker was shot and killed and one Afghan soldier was wounded. This is the second insider attack in a week. Initial reports indicated that the U.S. soldiers were killed but Resolute Support confirmed there were no USA or North Atlantic Treaty Organisation casualties.
The attack was reportedly by an afghan Soldier and it is termed as a insider act. In April, scores of Afghan soldiers were killed when militants breached security at Camp Shaheen, detonating explosives and shooting hundreds at a mosque and dining hall on the base.
The convoy returned fire in self-defense, and there were no U.S. casualties, according to a North Atlantic Treaty Organisation statement.
Gen. Dawlat Waziri, spokesman for the Afghan Defense Ministry, also confirmed the attack. "More information will be provided as it becomes available".
Defense Secretary Jim Mattis said this week that he will present a new United States military strategy for Afghanistan, along with adjusted troop numbers, in the coming weeks to President Donald Trump.
In a statement Wednesday, Mattis said that "this administration will not repeat the mistakes of the past".