A suicide bomber blew himself up during a Shiite Muslim religious ritual in the eastern Iraqi city of al-Sadiya on Thursday, killing at least 30 people and wounding 67, a senior local official and police said.
No group immediately claimed responsibility for the attack, which came on the final day of Ashura, a 10-day holy ritual when Shiites commemorate Imam Hussein, a grandson of the Prophet Mohammad.
The man detonated an explosives belt in a crowd of pilgrims, who were mainly Shiite Kurds, the sources said. Most of the wounded pilgrims were taken to hospitals in Iraq's northern Kurdistan region.
Shiites are considered apostates by hardline Sunni Islamist insurgents who have been regaining momentum in Iraq this year. On Wednesday at least 19 people were killed in similar bomb attacks targeting Iraqi police and pilgrims.
The government blames al Qaeda for the rise in violence in the country, saying it seeks to destabilize the Shiite-led government and foment inter-communal conflict.
Insurgent attacks in Iraq have risen since the start of the year, with hundreds killed each month. The growing violence has raised fears of a return to the heights of bloodshed seen in 2006-7, when tens of thousands died.