Bombers and gunmen attacked policemen and a wake in Iraq among other targets, killing at least 44 people across the country on Thursday, in the latest burst of violence that has raised concerns about a return to civil strife.

Gunmen opened fire on two checkpoints guarding oil installations on the road between Haditha and Baiji, 180 km (111 miles) north of the capital, killing 11 people, police said.

In the town of Muqdadiya, 80 km northeast of Baghdad, a further 11 people were killed when a car bomb exploded at a wake.

In eastern Baghdad, a car bomb killed four people, police and hospital sources said.

Three roadside bombs targeted police patrols in the city of Tikrit, killing three policemen. In the northern city of Mosul, three suicide car bombs targeted checkpoints killing four policemen, police said.

Earlier in the day, seven policemen were killed in attacks in the western province of Anbar, Iraq's Sunni heartland.

Around 60 km southwest of the ethnically mixed city of Kirkuk, gunmen attacked a checkpoint, killing three members of a government-backed Sunni militia known as Sahwa. In Kirkuk itself, a roadside bomb killed a fourth Sahwa member.