The Islamic State extremist group on Monday claimed an attack on Shiite pilgrims that killed at least 22 people and injured 30 others west of the Iraqi capital Baghdad.
A car bomb went off targeting a group of Shiite worshippers commemorating a holy imam in between al-Saidiya and al-Doura districts, a local police officer told dpa on condition of anonymity.
The number of casualties is expected to rise due to the severity of the injuries, the source added.
Islamic State is a radical Sunni militia that regards Shiites as heretics.
There were conflicting reports about the attack, with Islamic State claiming in a statement circulated on social media that 40 people were killed and dozens more injured in a suicide attack involving a car bomb.
The bombing had been part of a series of planned assaults against Shiites, it said.
The statement could not be independently verified by dpa.
On Sunday, at least 30 people were killed and 55 wounded in twin bombings claimed by Islamic State in the mostly Shiite southern town of Samawa.
A day earlier, 24 people were killed in a car bombing targeting Shiite pilgrims in a Baghdad suburban area.
Shiite pilgrims have been commemorating Moussa Ibn Jaafar al-Kazim, the Shiites' seventh holy imam, over the past few days, amid tight security measures carried out by joint army and police forces in and around Baghdad.