KABUL, Afghanistan — Three coalition soldiers were killed in southern Afghanistan on Sunday when a man wearing an Afghan police uniform turned his weapon against them, coalition officials said.

The incident appears to be the latest in a series of "green on blue" attacks on international forces by their Afghan partners.

The International Security Assistance Force, as the coalition is formally known, refused to confirm the nationality of the three soldiers, but most ISAF forces in southern Afghanistan are U.S. troops.

ISAF spokesman U.S. Army Major Adam Wojack told McClatchy that the shooter was detained after the attack, which happened around 5 p.m. It was not yet clear “whether he’s an actual member of the Afghan police or if he was an infiltrator in uniform,” Major Wojack said.

At least 80 coalition troops have been killed by the Afghans they were working with, according to the Pentagon. Half of those attacks have occurred since May 2009.

Two U.S. soldiers were killed and two others wounded in a “green on blue” attack at a joint Afghan-U.S. base in Kandahar province March 1. Two U.S. soldiers were killed by an Afghan soldier February 23 at a joint Afghan-U.S. base in eastern Nangarhar province.

Four French soldiers were shot dead by an Afghan soldier at a joint base in Kapisa province on January 20. A fifth soldier later died of his wounds.

The Kapisa killings prompted France’s then-president Nicolas Sarkozy to bring forward the departure date of French combat troops by a year, to the end of 2013. His recently-elected successor, Francois Hollande, has pledged to withdraw them by the end of 2012.

ISAF claims most attacks are carried out by Afghans who are frustrated with the behavior of their Western counterparts, not by Taliban infiltrators.

(Stephenson is a McClatchy special correspondent.)