Iraqi police say a car bombing in Baghdad has killed six people and
wounded at least nine others in the latest attack targeting Shi'ite
Saturday's attack took place as hundreds of thousands of people made their way to the city of Karbala for a festival marking the birth of the Shi'ites' 12th and last Imam.
About 30 Shi'ite pilgrims have been killed and dozens more wounded in attacks since Thursday.
Northeast of Baghdad, Kurdish officials have agreed to pull their troops from areas of Diyala province, and to hand over authority to the central Iraqi government.
A Kurdish minister, Jaffar Mustafa, says about 4,000 Kurdish troops, known as Peshmerga, will withdraw from the region over the next 10 days.
Kurdish forces have patrolled areas of ethnically mixed Diyala where many Kurds live, although the province is not part of Iraq's northern Kurdish region.
A U.S. military official says a branch of the Iranian Revolutionary Guards (Quds Force) and the Lebanese-based militant group Hezbollah are training Iraqi assassination teams in Iran.
He said they plan to target Iraqi officials, as well as U.S. and Iraqi troops.
The U.S. official, who requested anonymity, told Western news agencies the Shi'ite "special groups" are being trained in the Iranian cities of Qom, Tehran, Mashad and Ahvaz.
U.S. and Iraqi officials have accused Iran of arming Shi'ite militias in Iraq. Iran denies supporting the insurgents and says the U.S. military presence in Iraq is to blame for violence in the country.