BAGHDAD, Iraq – A judge on the special tribunal that will put Saddam Hussein and members of his former regime on trial was assassinated yesterday in the Iraqi capital, according to an Iraqi police official and a media report.

Judge Barwez Mohammed Mahmoud and a relative were killed yesterday in northern Baghdad’s Azamyiah district, the official said early today on condition of anonymity.

Al-Arabiya, the Dubai-based satellite TV news network, also reported that the judge and a relative died in an attack. The judge’s exact relationship to the other victim wasn’t immediately known. The network said they lived in the same house in northern Baghdad, near the attack site.

Officials with the Iraqi government and the Iraqi Special Tribunal couldn’t be reached before dawn today for comment.

Mahmoud’s role on the tribunal was unclear, but the law establishing it called for up to 20 investigative judges and up to 20 prosecutors. It also said the tribunal would have one or more trial chambers, each with five judges. The judges have not even been identified in public because of concerns for safety.

The killing came just one day after five former members of Saddam Hussein’s regime – including one of his half brothers – were referred to trial for crimes against humanity.

The announcement Monday by the tribunal marked the first time that the special court issued referrals, similar to indictments, which are the final step before trials can start.

No date was given for that trial.

Also yesterday, thousands of mostly black-clad Iraqis protested yesterday outside a medical clinic where a suicide car bomber killed 125 people a day earlier, braving the threat of another attack as they waved clenched fists, condemned foreign fighters, and chanted “No to terrorism!”

Police prevented people from parking cars in front of the clinic or the hospital, where authorities blocked the gates with barbed wire to stave off hundreds of victims’ relatives desperate for information on loved ones.

The demonstration in this town 60 miles south of the capital came as the Shiite candidate for prime minister traveled north for talks with the Kurds about a coalition government.

Insurgents fighting both American forces and the Iraqi government released a video yesterday of French journalist Florence Aubenas, 43, kidnapped nearly two months ago. The correspondent for the French daily Liberation appeared alone in front of a maroon-colored background, pleading for help.

Abu Musab al-Zarqawi’s terror group, which has repeatedly seized foreigners and attacked Americans, purportedly claimed responsibility for the suicide bombing in Hillah. It was not possible to independently verify the claim, which was posted on the Internet.

The group said it targeted recruits for the Iraqi security services, whom it referred to as “apostates,” but did not mention those killed in a nearby market. The car bomb went off at a medical clinic where police and army recruits were lining up for physical exams.

In Hillah, relatives and friends screamed and wailed as they gathered around lists of the dead and wounded that were posted on hospital walls. Relatives who came to identify the dead placed corpses in coffins and loaded them onto pickup trucks to take them away for burial.

Fears that insurgents would target Shiite mourners forced authorities to cancel an elaborate funeral procession for some of the victims of Monday’s attack, the deadliest since the insurgency began two years ago.

“I am afraid there might be a suicide bomber among the demonstrating crowd,” said 30-year-old Ahmed al-Amiry. “It’s very possible.”

But anxieties over another attack did not prevent more than 2,000 people from gathering outside the clinic yesterday, shouting “No to terrorism!” and “No to Baathism and Wahhabism!” and demanding the resignation Ayad Allawi, the interim prime minister.

The mention of Wahhabism was a clear reference to foreign fighters who are supporters of Al Qaeda and adherents of the strict Wahhabi form of Islam, which is the version practiced in Saudi Arabia. The Jordanian-born Mr. Zarqawi, the country’s most feared terrorist, claims to be affiliated with Osama bin Laden’s organization. The Baath party was the political organization that ran Iraq under Saddam Hussein.

Although Monday’s attack was directed at recruits, most of the victims were Shiites. Insurgents have increasingly targeted gatherings of Shiites, who make up 60% of Iraq’s population, in an apparent effort to start a sectarian war.

The Shiites have refrained from striking back, mostly at the behest of Grand Ayatollah Ali al-Sistani, who wants nothing to impede the Shiites from gaining political power in Iraq.