Officials said unidentified gunmen wearing Iraqi Army uniforms slaughtered the Kurds in a village in Diyala Governorate, east of Baghdad.
The Patriotic Union of Kurdistan said in a statement that the victims were Kurdish Shi'a.
The attack has been blamed on Al-Qaeda militants.
The U.S. military, meanwhile, has reported the deaths of five soldiers in four separate incidents in Iraq on May 18 and 19.
The U.S. military said the deaths occurred in the Baghdad area and the western Al-Anbar Governorate.
(compiled from agency reports)