The assassination occurred as more than 2,000 Iraqis protested outside a medical clinic in Hillah, a city 60 miles south of the capital where a suicide car bomber killed 125 people a day earlier.
The protesters in Hillah, braving the threat of another attack as they waved clenched fists, condemned foreign fighters and chanted ''No to terrorism!"
Another car bombing this morning killed at least six Iraqi National Guard members and wounded 28 in Baghdad. A police source told Reuters the bomb targeted Iraqis signing up for the army.
Mahmoud's role on the Hussein 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 been identified in public because of concerns for safety.
A day before the killings, five former members of 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 start. No date was given for that trial.
The five referred to trial Monday included Barzan Ibrahim al-Hassan al-Tikriti, one of Hussein's half brothers, and former vice president Taha Yassin Ramadan. The three others were senior Ba'ath Party members. Hussein was captured in December 2003, and others have been in custody for nearly two years.
US military officials transferred 12 of the top defendants to Iraqi custody in June with the handover of sovereignty. They're being held at an undisclosed location near Baghdad International Airport, west of the capital.
Yesterday's demonstration outside the medical clinic in Hillah was among several developments:
Two US soldiers were killed yesterday in a vehicle accident in Beiji, 155 miles north of the capital, bringing the number of American dead in the Iraqi war to 1,499.
