More than 100 Muslim pilgrims were trampled to death and some 1,000 injured outside the Saudi holy city of Mecca on Thursday, medical sources said.
The pilgrims were killed when they performing a stoning ritual at the annual Hajj.
The sources said the death toll was expected to rise because there are dozens of victims who have not been taken to hospitals.
Thousands of pilgrims rushing to complete a symbolic stoning ritual on the last day of the Hajj tripped over luggage Thursday, causing a stampede.
The Saudi Interior Ministry said in a statement that an unknown number of people were killed in the incident.
This was the second fatal incident in this year's Hajj.
Earlier this month, a building housing pilgrims collapsed in Mecca, leaving over 76 people dead and scores of others injured.