A suicide attack on a police checkpoint in the western Iraqi city of Ramadi has left at least five officers dead, police say.

Police Major-General Tariq Youssef said six policemen and four civilians were also wounded in the car bombing on Monday.

The attack, which took place in the Tamim area about 5km west of downtown Ramadi, came a day after another suicide bomber struck a neighbourhood patrol checkpoint in a Sunni Arab area of north Baghdad on Sunday, killing 15 people.

Ramadi, the capital of western al-Anbar province, was once one of the most dangerous places in Iraq when al-Qaeda in Iraq and its allies held sway there but has become safer since local Sunni Arab tribes population turned against al-Qaeda fighters in late 2006 and 2007.

Attacks still occur, however, and police and US-backed neighbourhood patrols are frequently targeted.