Thousands of Iraqi Shiites, many of them young men, walked to the holy city of Karbala on Wednesday to mark the birth of Imam Mehdi, believed to be the messiah in their faith.
Groups of young men and some black-shrouded women from Baghdad's Shiite strongholds like Sadr City were seen carrying white, green and red banners as they trekked the 100 kilometres (60 miles) south from the capital to Karbala.
"We are the Mehdi's cubs," read one white banner.
One side of the road to Karbala was closed to vehicles to ease the flow of pilgrims as forces from the country's fledgling national guard manned several checkpoints along the way.
Security was tightest around Karbala itself, with no cars allowed to enter the city within a radius of almost 10 kilometers (six miles).
A special grey-shirted force from Iraq's Shiite religious authority and mainstream political parties searched all those entering the centre of Karbala, home to the shrines of Imam Hussein and Imam Abbas.
The measures were aimed at preventing a repeat of the devastating double car bombings in Karbala and Baghdad that killed close to 180 in March during the commemoration of Imam Hussein's killing, known to Shiites as Ashura.
"We have many enemies including this Zarqawi group, which is nothing but a bunch of fanatics that have nothing to do with Islam," said a Shiite cleric who did not wish to be identified.
Jordanian-born Abu Mussab al-Zarqawi and his extremist Sunni Muslim Tawhid wal Jihad (Unity and Holy War) group are blamed for some of the worst attacks in Iraq and believed to be behind many kidnappings.
The group has professed its hatred for Shiites in several Internet statements, describing Iraq's majority community as "traitors and Jews".
Organisers of the Mehdi birth festivities, supposed to be a joyful event far removed from Ashura's demonstrations of self-flagellation, appeared determined Wednesday to keep supporters of radical Shiite cleric Moqtada Sadr in check.
The zealous Sadr partisans usually brandish at public events large posters of the young cleric and chant slogans attacking the US presence in Iraq and the government of Prime Minister Iyad Allawi.
Iraqi and US forces have been cracking down on Sadr's Mehdi Army in the slums of Sadr City and arresting many of his deputies, following a bloody August standoff in the holy city of Najaf.
The exit of Sadr's militia from Najaf and the peaceful end to the siege of the Imam Ali shrine there was mediated by Grand Ayatollah Ali al-Sistani, Iraq's highest Shiite authority.
Unlike Sadr, he favours a more moderate and non-violent approach to asserting the rights of Shiites, after decades of oppression under the ousted regime of Saddam Hussein.
Karbala itself was the site of some of the bloodiest fighting when the Mehdi Army kicked off its revolt against US occupation in April.
Imam Mehdi, who according to tradition disappeared mysteriously in the 9th century, is the last of the 12 Shiite imams (holy men).
Millions of Shiite Muslim around the world believe he will return to deliver humanity from darkness and strife.
Wednesday's festivities were to culminate with the floating of hundreds of candles on a river in Karbala near the site of a shrine paying tribute to the last imam.
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