At least 22 people have been killed in Iraq in a spate of mortar and bomb attacks, including one on a popular central Baghdad eatery at lunchtime.

Police said in the main northern city of Mosul a suicide bomber rammed a truck through the fence of Sheikh Fatihi police station and detonated explosives, killing at least six policemen.

A police official said around 25 people were wounded, including civilians, and the building was almost destroyed.

Two people died in the blast at the budget restaurant, frequented by labourers, in Tayaran square in the centre of Baghdad.

In another attack on civilians, two people died and seven were wounded when a bomb exploded in a shopping area in the central Karrada district.

According to a security official, the car primed with the bomb had been parked in defiance of new rules announced on Sunday which outlaw parking in the city centre to prevent bomb attacks.

Another car bomb in the same district, which targeted an armed convoy, killed five civilian bystanders and wounded nine, an official said.

He said two people in the mainly Shiite Abu Chir district in Baghdad's south were killed in a mortar attack.

Police earlier reported that five people, three of them brothers, were killed by a roadside bomb in the town of Al-Wahda, south-east of Baghdad.

Police official Mohsen Mohammed said the five were in a car heading to the Iraqi capital from Al-Wahda, about 40 kilometres away, when their vehicle was hit by the bomb.

Meanwhile the US military said 13 civilians and two policemen were killed when a suicide bomber blew up a vehicle against a police post in the western city of Ramadi late yesterday, raising a previously given death toll by one.

A military statement said police had ordered a suspicious truck to halt near the police post when the driver detonated the bomb.

- AFP