WASHINGTON (KABC) --A two-star U.S. general was killed in a shooting at a base in Afghanistan on Tuesday, officials said.
The senior officer was identified as Maj. Gen. Harold Greene. He was a native of upstate New York who received a master's degree and a Ph.D. from University of Southern California.
Authorities said a man dressed in an Afghan army uniform opened fire on local and international troops at Camp Qargha, a military base just west of Kabul.
"There are a number of causalities as a result of the shooting, perhaps up to 15, to include some Americans. Many were seriously wounded, others received only minor injuries. The assailant was killed," said Rear Admiral John Kirby with the U.S. Department of Defense.
The general is the highest-ranking U.S. officer to die in combat since 1970. Greene was the deputy commanding general, Combined Security Transition Command-Afghanistan. An engineer by training, Greene was involved in preparing Afghan forces for the time when U.S.-coalition troops leave at the end of this year.
A senior U.S. official told ABC News that 15 International Security Assistance Force personnel were wounded in the attack, and at least half of them are Americans. Germany's military said a German brigadier general was among the wounded. The senior official said it is believed the shooter was not an Afghan soldier, but somebody who acquired a uniform and managed to sneak on the base. The shooting remains under investigation.
Afghan President Hamid Karzai condemned the attack as "cowardly," and said it is "an act by the enemies who don't want to see Afghanistan have strong institutions."
The shooting comes as foreign troops prepare to withdraw by the year's end, and as so-called "insider attacks" -- incidents in which Afghan security turn on their NATO partners -- largely dropped last year.
ABC News and the Associated Press contributed to this report.