Reports are coming from Afghanistan today about a brutal shooting of American military personnel at an Afghan-NATO training base in Kabul.

From The New York Times:

A United States Army major general was killed on Tuesday by an Afghan soldier, shot at close range at a military training academy on the outskirts of Kabul, an official of the American-led coalition and Afghan media reported Tuesday. The officer was the highest-ranking member of the American military to die in hostilities in the Afghanistan war.

The coalition official, who spoke on condition of anonymity and would not release the name of the major general, said an unspecified number of other service members of the American-led coalition and Afghan soldiers, including a senior Afghan commander were also shot. Their conditions were not known.

Martha Radditz from ABC News reports the American general killed would be the highest ranking casualty of the entire Afghanistan war.

Other media reports say many more Americans were injured in the “insider attack.”

Details about the attack at Camp Qargha, a base west of the capital, Kabul, weren’t immediately clear. Gen. Mohammmad Zahir Azimi, a spokesman for Afghanistan’s Defense Ministry, said a “terrorist in an army uniform” opened fire on both local and international troops. Azimi said the shooter had been killed and that three Afghan army officers were wounded.

A U.S. official told The Associated Press that one American soldier was killed and “about a dozen” of the wounded were Americans, but declined to comment further. The official spoke on condition of anonymity because the official was not authorized to discuss details of the attack by name on the record.

A senior U.S. military official told Fox News that one of the dead was an ISAF service member and the shooting left a “significant number of wounded, both Americans and Afghans.”

Today’s shooting is the latest in a series of “insider attacks” — incidents in which Afghan security forces turn on their Western military partners. In 2013, there were 16 deaths in 10 separate “insider” attacks. In 2012, such attacks killed 53 coalition troops in 38 separate attacks.