The bombs planted in three cars went off almost simultaneously in the north of the city when dozens of believers were taking part in the Ashura ceremony commemorating imam Husein ibn Ali, the grandson of Prophet Mohammed, who is worshipped by Shiites.
At least 29 people were killed and 126 wounded Tuesday in eight car bombings in Iraq.
The car bombs rocked the city of Kirku, as well as several areas inside and outside Baghdad.
No one has yet claimed responsibility for the attacks, but car bombs may indicate Sunni insurgents who often carry out attacks against Iraq's Shiite majority.
Other reports suggest al-Qaeda in Iraq might be behind the bombings.
Three car bombings killed 14 Shi'ite Muslims during mourning processions in the Iraqi capital Baghdad on Tuesday, police and hospital sources said.
Dozens more were injured in the explosions. They struck during the holy month of Ashura, of special significance to Shi'ites who are prime targets of al Qaeda's Iraqi affiliate and other Sunni Muslim insurgents.
There was no immediate claim of responsibility for the attacks, but car bombs are a hallmark of Sunni insurgents who often carry out attacks against Iraq's Shiite majority.
Violence in Iraq has decreased dramatically from its peak in 2006 and 2007, when brutal sectarian violence swept the country, but attacks remain common.
Voice of Russia, TASS, RIA, Reuters, AFP, RT, CNN