Attacks mostly targeting members of Iraq's security forces killed 12 people on Sunday, the latest in an increase in violence in a country only a few years removed from a brutal sectarian war.

The violence comes amid myriad political rows and fears that civil war in neighbouring Syria could spill over into Iraq and plunge the country further into crisis.

The worst of Sunday's attacks targeted security forces, with bombings and gunfire killing four policemen in and around the main northern city of Mosul and three soldiers in the western province of Anbar, officials said.

Both areas are populated mostly by Sunni Arabs, the minority community that has for months railed against alleged government targeting and discrimination.

Analysts say the demonstrations, coupled with the authorities' response to them that protesters have deemed inadequate, have given militant groups fuel and room to manoeuvre.

In Baghdad, meanwhile, separate gun attacks killed five people, including a policeman.

Iraq is struggling to contain a wave of violence that has killed more than 440 people so far this month -- the second month in a row in which more than 400 people have died in unrest.

The violence has decreased from its peak in 2006 and 2007, but attacks remain common, killing at least 200 people each month so far this year.