Beating their chests and crying "Our beloved Hussein," the crowds moved south from Baghdad and Babylon towards the central city to mark the death in battle at Karbala in the year 680 of Hussein, a grandson of the Prophet Mohammad.

The commemoration, to culminate next Tuesday and Wednesday, was also expected to provide an opportunity for the Shiites to flex their new-found political muscle.

On the sides of the roads, where traffic was brought to a crawl by the crowds of walking pilgrims, makeshift shelters with portraits of Hussein had been set up to sell food from steaming pots to hungry worshippers.

There was only a small military presence on the road from Babylon to Karbala, where Hussein is buried and which lies some 80 kilometres (50 miles) southwest of Baghdad.

A few soldiers manned a checkpoint at a crossroads. They were from the Free Iraqi Forces, part of the US-backed Iraqi National Congress umbrella opposition group which sent 700 Iraqi exiles to fight alongside coalition forces.

Pilgrims, some of whom said they had been walking for 10 days, have come from all over Iraq, where Shiites make up around 60 percent of the population.

Saddam's ousted regime included no Shiites in senior leadership positions and, fearful of Shiite opposition to his rule, the deposed dictator had banned the Karbala pilgrimage.

Friday prayers resumed at the tomb of Hussein in Karbala this week after being banned in May last year by Saddam.

The cleric who led the prayers used the occasion to denounce the presence of US troops in the country, saying it amounted to imperialism by "unbelievers."

SPACE.WIRE