The Iraqi government has imposed a vehicle ban in most of Baghdad as thousands of Shi'ite pilgrims converge on the capital for Sunday's commemoration of the death of an eighth-century imam.
The ban is part of security operations intended to keep the pilgrims safe and will last from Friday evening (at 1700 UTC) until Monday morning (0200 UTC).
Experts say, however, with hundreds of thousands of pilgrims arriving in Baghdad, it may prove impossible to protect the entire religious festival. During last year's event, nearly one-thousand people died when rumors of a suicide bomber triggered a mass stampede on a bridge across the Tigris River.
The ceremonies are taking place as American and Iraqi forces are conducting a massive security operation in the Iraqi capital aimed at curbing sectarian violence threatening to plunge the nation into civil war.