(AP) -- An American general was killed in an apparent insider attack Tuesday by a member of the Afghan security forces, a Pentagon spokesman said, the highest-ranking U.S. Army officer to be killed in the Iraq or Afghanistan wars.

The spokesman, Rear Adm. John Kirby, said that the assailant, dressed in an Afghan army uniform, fired into a group of international soldiers at the Marshal Fahim National Defense University at Camp Qargha, a base west of Kabul, and was subsequently killed.

Another 15 people, roughly half of them Americans, were wounded. Among the wounded were a German brigadier general, two Afghan generals and an Afghan officer, whose rank the Afghan Defense Ministry did not provide.

The attack occurred during a site visit to the university by coalition members.

Ministry spokesman Gen. Mohammad Zahir Azimi, said a "terrorist in an army uniform" opened fire on both local and international troops.

The Qargha shooting comes as so-called "insider attacks" -- incidents in which Afghan security turn on their NATO partners -- largely dropped last year. In 2013, there were 16 deaths in 10 separate attacks. In 2012, such attacks killed 53 coalition troops in 38 separate attacks.

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