At least 40 others were wounded in the attack and the death toll was expected to rise, said Brig. Gen. Rahim al-Jibouri, commander of Tal Afar police.

The attack occurred in a crowded Shiite neighborhood of the mixed city, 260 miles northwest of Baghdad.

The attacker drove a dump truck filled with explosives and covered with a layer of gravel, Brig. Najim Abdullah.

Within an hour of the attack, authorities imposed a complete curfew on the city, said Abdullah, who also is mayor of Tal Afar.

Rescue workers were still digging in the rubble for more victims.

Tal Afar - a city which the US military initially cited as success story after major operations were said to have cleared the city of insurgents - has been the frequent site of Sunni attacks in the past year.

Many of them stemmed from allegations by a 50-year-old Sunni Arab woman, who came forward last February and said Iraqi soldiers raped her when they raided her house searching for weapons. Sunni insurgents have kidnapped and killed dozens of Iraqi security officials in response.

The city also recorded one of the deadliest days since the start of the Iraq war, when at least 152 people died in truck bombings on March 27.

Meanwhile in Baghdad, a roadside bomb killed nine civilians and wounded eight during rush hour Monday morning, police said.

The bomb had been planted at the Zaafaraniyah intersection in the Jisr Diyala area, a predominantly Shiite neighborhood, an officer said on condition of anonymity because he was not authorized to speak to media. The route is frequently used by Iraqi police and army patrols.

The explosion occurred around 7:30 a.m., and all the victims were pedestrians, the officer said.