KARBALA: A mortar bomb attack on the last day of a major mourning ceremony in Iraq killed 31 pilgrims and wounded dozens more on Friday in an atrocity blamed on Al-Qaeda and Saddam Hussein loyalists.

The bomb struck pilgrims who were leaving the holy shrine city of Karbala, 110 kilometres (68 miles) south of Baghdad, where more than a million devotees had gathered to mark the festival of Arbaeen.

It was the third major attack this week on worshippers who have for weeks been travelling there on foot for the climax of the event earlier on Friday.

A provincial health ministry official gave the death toll and said 150 others were wounded.

“A mortar round was launched from fields northeast of the city,” provincial governor Amalheddin al-Hir told a foreign news agency.

“I accuse Al-Qaeda who are being supported by the Baath party,” he said, referring to Saddam’s outlawed political movement.

Arbaeen marks 40 days after the Ashura anniversary commemorating the slaying of Imam Hussein, one of Shiite Islam’s most revered figures, by the armies of the Sunni caliph Yazid in 680 AD.

A series of suicide attacks have seen dozens of pilgrims killed in recent days.

Hir said earlier that 10 million worshippers had visited the Imam Hussein shrine in the past two weeks, walking as a sign of piety, with the ceremonies culminating at midday (0900 GMT) on Friday.

“The visitors included Arabs and about 100,000 foreigners from the Gulf states, Syria, Lebanon, Iran, Tanzania, the United States, Norway and Belgium,” Hir said.

Television pictures showed crowds massed near the shrine stretching into the far distance and carrying flags adorned with Imam Hussein’s image.

Around 30,000 police and soldiers were on duty in the holy city, following the recent spate of attacks.