http://www.reuters.com/article/idUSTRE70E0TS20110115
EXCERPT:

MOSUL, Iraq | Sat Jan 15, 2011 8:39am EST

MOSUL, Iraq (Reuters) - Two U.S. soldiers were killed and a third was injured when two Iraqi soldiers opened fire on U.S. troops during training in the northern city of Mosul on Saturday, Iraqi army sources said.The incident occurred while U.S. soldiers were training an Iraqi military unit at al-Ghazlani U.S. military camp in southern Mosul, 390 km (240 miles) north of Baghdad, they said.
"According to available information, two American soldiers were killed today during a shooting at a training session inside al-Ghazlani military camp. Two Iraqi soldiers suddenly opened fire at the American soldiers," an Iraqi military colonel in Mosul, who declined to be named, said.
The U.S. military said in a statement two U.S. service members were killed and one was wounded while conducting operations in northern Iraq, but did not give further details.
"Until now, we don't have any information on why the two Iraqi soldiers opened fire," a senior police official said.
The police and army sources both said the two Iraqi soldiers had been arrested, although it was unclear if they were being held in Iraqi or U.S. custody.
Another Iraqi military colonel said an initial report indicated that one of the Iraqi soldiers had also been killed.
"We have an initial report that one of the Iraqi soldiers who opened fire was killed by American forces, but it's not confirmed yet," he said.
Separately, another U.S. service member was killed while conducting operations in central Iraq, the U.S. military said in a statement on Saturday. It gave no further details and did not specify where the incident occurred.
Fewer than 50,000 U.S. troops remain in Iraq since the United States officially ended combat operations last August. The remaining soldiers are focused on advising and assisting Iraqi security forces as they take the lead in the fight against a weakened yet resilient insurgency.
Bombings and attacks remain a daily occurrence in Iraq, although violence has fallen since the height of sectarian fighting in 2006-7 unleashed by the 2003 U.S.-led invasion.
Mosul remains one of the most dangerous cities in the country, where Iraq is still fighting a stubborn Sunni Islamist insurgency.
(Reporting by Jamal al-Badrani; Writing by Ahmed Rasheed; Editing by Serena Chaudhry)