US soldiers and Iraqi police had just sat down for lunch inside a police building in Mosul. Flak vests and other protective gear were removed. A door to the room was left ajar - just wide enough for the barrels of Iraqi police AK-47s to be poked inside. The attackers fired.
Then again. The suspected gunmen _ an Iraqi police officer still in his teens and a young sergeant _ ran toward a waiting car with return fire kicking up dust around them. The car swerved around a checkpoint and the attackers were gone. They are still missing.
The February 24 shooting _ which killed a US soldier and an interpreter and wounded five others _ was an alarming inside job that reinforced what many fear: insurgents and sympathisers possibly infiltrating the ranks of Iraq's security forces. The US military called it an "isolated incident."
This is true in one regard: The shooting was one of the few irrefutable examples of deadly turncoats inside the Iraqi forces. On Saturday, an Iraqi soldier killed two American soldiers and wounded three at a combat outpost 12 miles (20 kilometers) south of Mosul, the US military said. Iraqi authorities described the attacker _ who was killed in the gunbattle _ as a rank-and-file soldier who also served as a Sunni Muslim preacher for his unit. But the worry of infiltration is not a new one. During the early stages of the Sunni insurgency in 2004, officials in Baghdad and the Pentagon suggested moles in the security forces were leaking information about troop movements or helping carry out attacks.