Millions of Shiite pilgrims commemorated the birth of a central figure in Shiite Islam on Friday morning under heavy security measures after a series of recent attacks targeting worshippers.
They gathered in the central shrine city of Karbala to commemorate Imam Mehdi's birth, with children lighting 1,176 candles, representing the number of years since the birth of Shiite Islam's so-called 12th imam.
Worshippers also marched to a holy site once visited by the imam, which lies around one kilometre (0.6 miles) away from the centre of Karbala. They also chanted religious poems and shared foods and sweets with each other.
"The Shabaniyah visit ceremonies ended successfully without any security violations," Karbala provincial Governor Amal al-Din al-Har told AFP.
Authorities estimated that six million Iraqi visitors came to Karbala for the ceremonies, along with 150,000 foreign pilgrims.
Security forces this month began blocking roads leading to the shrine of Imam Hussein, the grandfather of the 12th imam, in the centre of Karbala, where the ceremonies were held.
Security was further tightened after twin car bombs in a market near Karbala killed four people on Tuesday.
Some 38,000 soldiers and police were helping secure the city, with measures including 2,000 policewomen for women-only checkpoints, sniffer dogs and explosives detecting devices, officials said.
Shiite pilgrims are a frequent target for Sunni insurgents, especially during times of commemoration ceremonies.
The rituals came amid a spike in attacks in Iraq, with the country suffering a wave of unrest in June. At least 282 people were killed, according to an AFP tally, although government figures said 131 Iraqis died.
So far this month, 62 people have been killed in attacks, with the deadliest of the violence striking Shiite towns and cities.
While unrest in Iraq has declined dramatically since its peak in 2006-2007, attacks remain common across the country.