Three car bombings killed 23 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.
Attacks on Iraqi Shi'ites tend to increase during Ashura, but Tuesday's was the first major one so far this year.
The deadliest attack on Tuesday occurred in the Shuala district, where a car bomb parked outside a Shi'ite place of worship exploded as people were leaving the building, killing nine.
"I saw lots of blood on the ground," said policeman Hashem Abbas, who witnessed the blast. He said shoes and torn clothing were scattered around the area.
Two other blasts killed seven people each.
Violence in Iraq has eased since the carnage of 2006-2007, but Sunni Islamists still launch frequent attacks, seeking to reignite sectarian strife and undermine the Shi'ite-led government's claim to provide security.