KARBALA: Twenty million pilgrims, swelled by a record influx of Iranians, have converged on the Iraqi shrine city of Karbala to mark Arbaeen, an annual Shia festival that climaxes on Saturday.

It is one of the world’s biggest religious gatherings, keenly obse­rved in Iraq and neighbouring Iran, both Shia majority countries.

The event marks the end of a 40-day mourning period for the killing of Imam Hussein - a founding figure in Shia Islam and grandson of the Prophet Muha­mmad (PBUH) — by the forces of Yazid in 680 AD.

So far, there has been little sign of the intra-Shia political tensions that have prevented Iraq forming a new government since elections nearly a year ago.

“It’s as if I’ve arrived in paradise,” said Najme, a 37-year-old primary school teacher, wrapped in a black chador and her feet clad in sneakers.

Along with her husband and parents, she is among more than three million Iranians attending the pilgrimage in Karbala, a new record, according to the Iranian government spokesman.

The family drove from the Iranian clerical centre of Qom to Najaf - a second holy city in Iraq - and then walked 80 kilometres (50 miles) to Karbala, home to the shrines of Imam Hussein and his brother, Abbas.

Najme’s mother Latifa could not disguise her joy. “I keep calling the family back in Iran I send them photos and videos, to share the atmosphere with them,” she said.

Iranian pilgrims have flocked to the event this year in part due to Baghdad and Tehran waiving visa requirements for travel between the two countries since late last year.

But the influx of pilgrims has filled hotels and sent room prices soaring. Some have even resorted to bedding down on pavements.

The pilgrims press forward on the esplanade, and among alleys that snake around the two mausoleums that sparkle with gold and blue under the unrelenting sun.

At night, processions are bathed in neon light.

Men dressed in black jump up and down on the spot, beating their torsos to the rhythm of religious chants blaring from loudspeakers.

Some cry hot tears, others slap their faces, to mark the killing of Imam Hussein centuries ago in the Karbala desert.

Among the 20 million pilgrims — up from 17 million last year —are five million foreign visitors, according to figures released by Baghdad.

Iran is of course the key external source.

“Arbaeen is an opportunity... for working class Iranians to travel” and celebrate what is both a religious and social occasion, said Alex Shams, who is researching a doctorate on the politics of Shia Islam at the University of Chicago.

“It’s almost impossible for Iranians to get visas to other countries,” he noted, and US sanctions have made the Iranian rial almost worthless. “Iraq is really one of the few countries that... they can afford to visit.” Arbaeen is similarly politically significant in Iraq, which has been mired in crisis since elections last October.