The Iraqi health ministry said on Tuesday that 31 people had been killed and 100 others wounded in a stampede during Shiite Ashura celebrations in the city of Karbala.
The ministry, said that 10 of the wounded were in serious condition.
According to Iraq’s official news agency INA, medical and security sources said that the toll is likely to increase.
Tens of thousands of Shiite Muslims converge on the holy city for the occasion, which marks the anniversary of the death of Imam Hussein, one of the grandsons of Prophet Mohammed.
People marched through Karbala, whipping their backs and chests with chains and sobbing as blood covered their bodies and faces. Others tapped their chests in a steady rhythm.
Millions of Shiites across Iraq are marking Ashura, which falls on the 10th of Muharram, the first month of the Islamic lunar calendar.
The Iraqi government had declared Tuesday a national holiday and deployed thousands of army and police forces to keep the peace at the celebrations.
Ashura is marked by Muslims to commemorate the day Moses was saved from the Egyptians.
However, for Shiite Muslims the day has special significance, marking Hussein’s death at the Battle of Karbala in Iraq in 680 AD.
The festival was banned in Iraq for years under dictator Saddam Hussein, who was ousted in 2003.