At least four people have died in a suicide car bomb attack targeting a police convoy in central Baghdad.
Several vehicles were set alight by the blast
At least 10 more people, including two policemen, were also hurt when the bomber rammed his car into the convoy.
The attack took place in front of the concrete blast walls surrounding the former ministry of education.
The latest outbreak of violence, which has led to more than 400 deaths, began after Iraq's new government was announced on 18 April.
Several cars caught fire in the explosion and thick black smoke billowed above the scene as firefighters doused the flames, watched by blood-stained survivors waiting for medical assistance.
"I was riding in one of the cars in the convoy when a car overtook us and exploded against the leading patrol car," policeman Mustafa Rasul told news agency AFP.
Most of the victims were civilian passers-by, police sources said.
In separate developments:
- a roadside bomb in Baghdad's southern district of Dura kills three civilians, believed to be street cleaners
- a suicide bombing against an Iraqi-US patrol in the northern city of Mosul kills two and injures a policeman
- four US marines die of wounds sustained after their vehicle hit a bomb in a week-long operation in western Iraq
The latest casualties bring the US death toll from Operation Matador in western Iraq to 9, and the total across the country to 25 over the last week, US forces said.
US commanders say that at least 100 insurgents and foreign fighters have been killed in Operation Matador.
The operation was launched to crack down on militants active in the rebellious Anbar province, from where they are believed to plot suicide bombings and attacks carried out in other parts of the country.
The US believes they cross into Iraq from Syria, but Damascus denies the accusations.