Baghdad and London are discussing a prisoner transfer deal that could see a British security guard convicted of murder in Iraq serve the remainder of his sentence in his home country, officials said.

Justice Minister Hassan al-Shammari has been invited to London to finalise and sign a memorandum of understanding over the transfer of convicts between the two countries, and while the deal would not solely affect Danny Fitzsimons, he would be a key beneficiary.

Fitzsimons became the first Western contractor to be convicted of a crime by an Iraqi court when he was sentenced to life in prison, equivalent to 20 years in jail under Iraqi law, in February 2011 for killing a Briton and an Australian in Baghdad's heavily-fortified Green Zone in August 2009.

"The British are insisting to make an agreement with Iraq, to take Danny Fitzsimons," justice ministry spokesman Haidar al-Saadi told AFP.

"We received an invitation from the (British) ambassador to go there and sign the agreement."

Speaking on condition of anonymity, a British diplomat told AFP that the deal was "not targeted at any specific individual, but that's not to say he (Fitzsimons) won't benefit from it."

Fitzsimons, a former British soldier who suffered from post-traumatic stress disorder, had insisted throughout his trial that he had acted in self-defence during an alcohol-fuelled brawl.

He told the court in west Baghdad that fellow Briton Paul McGuigan and Australian Darren Hoare had burst into his room and pinned him down before pointing an M4 rifle at his face, prompting him to use his pistol to kill them. He also wounded an Iraqi guard before being detained.

Fitzsimons was the first Westerner to be tried in Iraq following the US-led invasion of 2003.

Foreign security contractors had not been subject to Iraqi law until the beginning of 2009, when a security agreement between the United States and Iraq lifted their immunity.

Shiites flood Iraq shrine city for mourning rituals
Karbala, Iraq (AFP) Jan 3, 2013 - Shiite pilgrims from across Iraq and around the world thronged the shrine city of Karbala on Thursday for the climax of annual mourning rituals amid tight security over fears of militant attacks.

An AFP correspondent said massive crowds of people flooded the streets of the city, which officials say has seen millions of visitors in the run-up to the Arbaeen commemorations, as sad songs blared from loudspeakers.

Black flags fluttered alongside pictures of Imam Hussein and his half-brother Imam Abbas, revered figures in Shiite Islam who are buried in Karbala, which lies 110 kilometres (70 miles) south of Baghdad.

Provincial governor Amal al-Din al-Har said he expected some 15 million worshippers would have passed through the city by the end of the commemorations, many walking for days from across Iraq despite threats of violence by Sunni insurgents.

Among them are around 600,000 pilgrims from 30 different countries, leaving all of the city's 700 hotels packed to the brim.

Arbaeen marks 40 days after the Ashura anniversary commemorating the slaying of Imam Hussein by the armies of the caliph Yazid in 680 AD.

"We are defying terrorism, and we are following the example of Karbala in sacrifice and redemption," said 40-year-old Mohammed Swadi, who noted that he had walked for 12 days from the southern port city of Basra for the occasion.

"This is not much when it comes to expressing our love for Imam Hussein."

Another pilgrim said she had walked for three days from the central city of Hilla in order to attend Arbaeen in Karbala, to pray for a cure for a skin disease.

"I have a skin disease that doctors could not treat, and I vowed to attend the pilgrimage walking on foot, and ask Allah with the name of Hussein to cure me," said the 35-year-old woman who gave her name as Umm Ali, or mother of Ali.

The threat of insurgent attacks has spurred authorities to deploy 35,000 soldiers and policemen to Karbala, including 2,500 policewomen at checkpoints across the city, with aerial surveillance also watching over pilgrims.

Attacks on Shiites in the past week alone have left at least 12 people dead, two of whom were killed in an explosion while walking along the route from Baghdad to Karbala on Wednesday.

The seventh century battle near Karbala is at the heart of the historical division between Islam's Sunni and Shiite sects, a split that fuelled sectarian violence between Iraq's majority Shiite and smaller Sunni population since the 2003 US-led invasion.

Shiites make up around 15 percent of Muslims worldwide. They represent the majority populations in Iraq, Iran and Bahrain and form significant communities in Afghanistan, Lebanon, Pakistan, India and Saudi Arabia.

Now-executed dictator Saddam Hussein's Sunni-dominated regime barred the vast majority of Ashura and Arbaeen commemorations.