Baghdad (CNN) -- Two American troops were killed while conducting operations in northern Iraq on Sunday, the U.S. command in Baghdad announced, bringing the monthly death toll in the officially non-combat mission there to 11.
No details of the attack were released late Sunday.
The U.S. toll for the month to date ties April's previous high as the worst since the U.S. combat mission officially ended in August 2010. The last double-digit total was in November 2009, before the American presence became an advisory mission.
U.S. commanders say Shiite militias have stepped up attacks on Americans in recent weeks as Iraqi officials debate whether to ask U.S. forces to stay beyond the end of 2011.