A suicide attacker detonated a car bomb north of Baghdad today, killing 12 Iraqis – all but one of them National Guards – in another strike against those co-operating with American forces, the US military said.

Rebels launched multiple attacks on Iraqi police posts around the city of Tikrit killing 23 people – including 18 policemen – a day after the major Sunni Muslim political party pulled out of the campaign for the January 30 elections citing the deteriorating security situation.