Baghdad, Iraq - The death toll rose to more than 800 this morning after rumors of a suicide bomber led to a stampede in a vast procession of Shiite pilgrims as they crossed a bridge on their way to a shrine in northern Baghdad.
Most of the dead were crushed or suffocated, witnesses said, but many also fell or jumped into the Tigris River after the panicking crowd broke through the bridge's railings.
The pilgrims were among a throng of hundreds of thousands who had converged on the capital over the preceding day to mark the anniversary of the death of Imam Musa al-Kadhim, one of Shiite Islam's holiest figures.
Fear had begun spreading in the crowd an hour earlier, after insurgents fired rockets and mortars near the shrine, killing seven pilgrims and wounding two dozen, and leading to a counter-attack by American military helicopters.
But the stampede, which caused the greatest one-day loss of life since the American invasion in March 2003, appears to have been caused by unfounded rumors of a man wearing a suicide belt in the crowd.
At least 841 were killed and at least 323 people were injured, an Interior Ministry official said early this evening in Baghdad.
In the aftermath of the disaster, with tens of thousands of pilgrims continuing their procession, black-clad Shiite women could be seen keening over dead bodies in the streets of Khadimiya, the Shiite neighborhood where Imam Kadhim's shrine is located.
On the bridge itself, hundreds of sandals and shoes lay in piles. Local hospitals were overwhelmed, with the halls lined with dead bodies, some of them drenched in river water.
Insurgents have often attacked Shiites during religious processions over the past two years, and Iraqi authorities had blocked off roads throughout northern Baghdad starting Tuesday evening, anticipating attacks on the hundreds of thousands of Shiites who were converging on the capital.
Health Minister Abdul-Mutalib Mohammed said on Iraqi television that there were "huge crowds on the bridge and the disaster happened when someone shouted that there is a suicide bomber on the bridge."
"This led to a state of panic among the pilgrims," he said, "and they started pushing each other and there were many case of suffocation."
The panic was confirmed by Brig. Jaleel Khalaf, security commander for the Khadimiya district, in northern Baghdad on the western bank of the Tigris.
The bridge where the stampede took place links a Shiite neighborhood with a Sunni area that has long been a stronghold of support for Saddam Hussein and the insurgency.
The stampede came at a time of high sectarian tensions, days after the new draft constitution was presented to Iraq's Parliament over the angry objections of Sunni representatives.
Many leading Sunnis have called for voters to reject the document when it goes before a nationwide referendum in October, and there have been demonstrations against the charter by Sunnis in central and northern Iraq.
Prime Minister Ibrahim al-Jaafari, a Shiite, released a statement of condolence to the victims of the stampede and their families and declared a three-day national mourning period.