Insurgents detonated a roadside bomb at a US military patrol in Baghdad on Monday and attacked a medical team sent by a helicopter to evacuate the wounded, the US military said.

The attack took place at Dora neighborhood in southern Baghdad, but it was not clear how many US soldiers were wounded or killed in the incident, the military said.

Also in Baghdad, three Iraqis were killed, including an Iraqi intelligence officer, police said.

"A police patrol found a body riddled with bullets, inside a car in eastern Baghdad," a police officer said, adding that "after investigations we identified the victim as an officer from the new Iraqi intelligence."

Elsewhere in the capital, a female official and her driver, working for a mobile communication company, were shot dead by unknown gunmen who fled the scene after the attack, police said.

The motive of the assassinations was not clear, they said, adding that investigations were underway.