US troop reinforcements have begun arriving in Baghdad to help Iraqi forces try to regain control of the streets amid worsening sectarian violence that US generals fear is pushing the country towards civil war.
In the northern town of Tikrit, a suicide bomber blew himself up at a mourning ceremony, killing at least 10 people and wounding 20, police said.
Iraq's Ministry of Defence on Sunday confirmed the arrival of the first units of the 172nd Stryker Combat Team in Baghdad from the northern city of Mosul after US soldiers were seen patrolling some of the capital's predominantly Sunni districts.
The units are equipped with the US military's newest armoured combat vehicle, the eight-wheeled Stryker, which military officials say is better suited to the urban terrain and will provide troops with more manoeuvrability and firepower.
US Defense Secretary Donald Rumsfeld last month extended the year-long tour of 3,700 troops from the 172nd by four months and redeployed them to Baghdad to help curb communal bloodshed that continues to kill scores every week.
The decision was seen as an admission the seven-week-old Operation Forward Together, a security crackdown in the capital driven by 50,000 mostly US-trained Iraqi forces, had failed to quell the daily car bombings, shootings and kidnappings.
Last night, three Multi-National Division soldiers were killed by a roadside bomb southwest of Baghdad, the US military said in a statement. There was no immediate word on the nationalities of the soldiers or details on the attack.
Also yesterday, police they had found 12 bodies around the capital, while gunmen also shot dead a policeman on Saturday. Eleven of the bodies had been tortured; all had been shot in the head, typical features of sectarian killings.
In Ishaqi, 100 km (60 miles) north of Baghdad, gunmen in three cars attacked two trucks carrying razor wire heading to a nearby US base, killing four Iraqis and setting the vehicles ablaze, police said.