BAGHDAD, Iraq - Gunmen killed a judge and lawyer working for the special tribunal that will try Saddam Hussein and members of his former regime, the first court staff killed since it was set up in late 2003 after the dictator was toppled, officials and a relative of the slain men said today.

News of the deaths came as two car bombs exploded in the capital, killing 10 Iraqi soldiers and wounding dozens of others. The first blast targeted an Iraqi army base in central Baghdad, killing six troops and wounding at least 25. A second car bomb an hour later at an army checkpoint in south Baghdad killed four soldiers, police said.

Judge Barwez Mohammed Mahmoud al-Merwani and his son, lawyer Aryan Barwez al-Merwani, were shot and killed Tuesday in Baghdad's northern Azamyiah district, said another of the slain judge's son, Kikawz Barwez Mohammed al-Merwani.

The son said unidentified gunmen in a speeding car raked the pair with gunfire as they were trying to get into a vehicle outside their home.

The killings came one day after the court issued referrals for five former regime members - including one of Saddam's half brothers - for crimes against humanity. Referrals are similar to indictments, and are the final step before trials can start.

However, a tribunal official, who asked not to be named, said the judge was not killed because of his job.

"He was not killed because he was working at the tribunal," he said. "It was something personal. I don't have details, but investigations are still going on."

The judge's surviving son disagreed, saying the two were assassinated either because they worked for the court, or because they were minority Kurds.

The tribunal official said Tuesday's killings are the first of any staff working on the Iraqi Special Tribunal, which consists of more than 60 investigative, appellate and trial judges. An official familiar with the court said al-Merwani was an investigative judge.

Judges and other legal staff working at the court have not even been identified in public because of concerns for their safety, and tribunal officials have kept a low-profile for the same reason, even refusing to say where the court is located.

The announcement Monday by the tribunal marked the first time that the special court issued referrals. No date was given for that trial.

The five referred to trial included Barzan Ibrahim al-Hassan al-Tikriti, one of Saddam's half brothers, and former vice president Taha Yassin Ramadan. The three others were senior Baath Party members.

Meanwhile, the first car bomb exploded outside an Iraqi army base in central Baghdad that occupies the former Muthanna airport, which has been targeted by insurgents several times over the last year.

An Interior Ministry security official, Ayad Hadi al-Maliki, said six people were killed and 25 people were wounded in the blast, 15 of them civilians.

Police officer Salam Hashim Mahmoud said the bomber drove up to the base gate, where army recruits normally line up to apply for jobs. Residents said Iraqi security forces opened fire after the incident.

About an hour later, another car bomb exploded in southern Baghdad's Doura neighborhood, killing four Iraqi soldiers at an army checkpoint and wounding three others, police said on condition of anonymity.