Women and children watch US Marines search a house in Haditha, 250 km northwest of Baghdad. (AFP)

Baghdad, March 2 (Reuters): Gunmen in Baghdad shot and killed a judge working for the Iraqi special tribunal set up to try Saddam Hussein and his top lieutenants, interior ministry officials said today.

Judge Barawiz Mahmoud and his son, who worked as a lawyer, were killed as they left their home in north Baghdad yesterday.

Mahmoud's other son Maryon said the attack was politically motivated because his father was seeking to bring Saddam and former members of his Baath party to justice.

'I was sleeping and I heard shooting. I came out and saw blood running from my father's neck. My father was shot twice and my brother 11 times,' he said near the scene of the shootings. A female relative wailed inside the home.

'We knew this was coming because of my father's work. He and my brother died holding their heads up high. This gives me comfort.'

The judge's death was the first assassination of a member of the special tribunal, which includes around 50 trial judges, investigating magistrates, prosecutors and appeals court judges.

Elsewhere in the capital, two car bombs killed 13 Iraqi soldiers and wounded dozens. Al Qaida's wing in Iraq, led by Jordanian militant Abu Musab al-Zarqawi, claimed responsibility for the bombings.

One of the blasts was outside an Iraqi army base used as a recruitment centre. Six soldiers were killed and 38 people were wounded, police said. A second car bomb targeted a convoy of Iraqi soldiers, killing seven and wounding two.

'On Wednesday morning, a lion from the martyrs' brigades of Al Qaida Organisation for Holy War in Iraq carried out a heroic attack on a centre of the apostate guards,' Zarqawi's group said in a statement which indicated it was a suicide bombing.

In a separate statement posted on Islamist websites, it claimed the attack on a convoy of 'apostate guards'.

'Today there is an epic battle ... and we shall continue on the path of jihad until the country is ruled by God's law.'

Guerrillas fighting to overthrow the US-backed government have repeatedly attacked Iraqi police and soldiers, as well as people lining up to take jobs in the security forces.

The judge's killing came a day after the tribunal referred its first charges against defendants, saying it had enough evidence to put five former Baath party officials on trial, including Saddam's half- brother Barzan Ibrahim al-Hassan al-Tikriti and former Deputy Prime Minister Taha Yasin Ramadan.

The trial is not expected to begin for at least another seven weeks. Saddam, who briefly appeared before a judge last July, is expected to be tried next year on war crimes charges.

Iraqi officials involved with the special tribunal say they hope the trials of Saddam's top deputies will help build a case against the former dictator.

Saddam loyalists and foreign militants, some loyal to Zarqawi, are behind much of the violence plaguing Iraq.