Police in northern Iraq say a truck bombing near a Shi'ite mosque has killed at least 63 people and wounded about 170.
The attack occurred near the city of Kirkuk Saturday, as worshippers left the mosque following midday prayers. Some 25 homes were destroyed.
Medical officials say women and children are among the dead. Rescue teams are searching for more victims.
No one has claimed responsibility for the attack.
Tensions have risen in the oil-rich region as the Kurdish majority seeks to incorporate it into their semiautonomous region despite opposition from other ethnic groups.
The blast comes 10 days before the United States is scheduled to pull its combat forces out of Iraqi cities.
The level of violence has dropped significantly across the country in the past year. But Iraqi officials have warned that insurgents will increase attacks in an effort to undermine confidence in the country's security forces.