Sept. 10 (UPI) -- Panic erupted at a Muslim shrine south of Baghdad Tuesday when part of a walkway collapsed, causing a stampede that killed at least 31 people and injured 100 others.
The incident happened toward the end of the procession.
The Shia pilgrims were celebrating the holy day of Ashoura in Karbala when the walkway fell. Most of the casualties occurred from people trampling one another. The death toll could rise, health officials warned.
Hundreds of thousands of Shia pilgrims visit Karbala every year for the holiday.
The shrine commemorates the death of Hussein, Prophet Muhammad's grandson, in 680. The event solidified the divide between the Sunni and Shia branches of Islam. The ceremony was banned during the rule of Saddam Hussein, a Sunni.
The day is typically marked with rallies, prayers and self-flagellation, where people whip their backs and chests. Others use a scalpel or a sword to cut their forehead so streams of blood come out. It's celebrated in other countries, including Iran, Pakistan, Afghanistan, India and Lebanon.