BAGHDAD — Gunmen assassinated a high-ranking Sunni judge as he headed to work in Baghdad on Monday, the latest of thousands of professionals killed in unsolved cases since the ouster of Saddam Hussein's regime in 2003.

Appeals Court Judge Amir Jawdat al-Naeib was slain a week after police arrested a group of militants who specialized in intimidating or killing doctors, academics and judges, according to an Interior Ministry official.

The aim of such attacks is to empty the country of professionals and scientists, said the official, who spoke on condition of anonymity because he was not authorized to talk to the media.

Under Saddam's Sunni-led regime, members of the now-dissolved Baathist party made up much of Iraq's professional class, including senior bureaucrats who knew how to run ministries, university departments and state companies. After his overthrow, senior Baathists were purged from their jobs, some were assassinated and many fled the country.

A key piece of legislation adopted Sunday by Iraq's parliament would allow thousands of low-ranking former Baathists to return to government jobs. But many former Baathists say they would not take such positions back, fearing Shiite death squads would hunt them down.

Some Iraqis blame Iranian-backed militias and hit squads for many of the killings — particularly of former army officers who took part in Iraq's ruinous 1980-88 war with Iran. Criminal gangs are also believed to be involved in some cases.

Al-Naeib, who was also a member of the Supreme Judicial Council which oversees the courts and jails, was ambushed by gunmen in two cars in the Mansour district of western Baghdad as he was being driven from his home, police and Deputy Justice Minister Busho Ibrahim said. His driver was also killed.

It was not known who was behind the killing or what the motive was, and authorities were investigating.

In another recent attack on a member of the judiciary, an investigative judge in the northern city of Kirkuk, Zaher al-Bayati, narrowly escaped assassination in October when gunmen in a vehicle opened fire on him, killing two of his bodyguards.

On Monday, a booby-trapped house in a small town northeast of Baghdad that had been a major center of Baathist support exploded as Iraqi police searched the building. The attack killed a police officer and two members of the local Awakening Council, a Sunni Arab group that switched sides to join U.S. forces against al-Qaida in Iraq.

Seven people were wounded in the attack in Buhriz, according to the local police chief, Col. Yahya al-Khishali. He said some Awakening Council members had been escorting the police in the search operation.

Haji Uday, the senior leader of the local Awakening Council in the nearby city of Baqouba, was killed Monday when the vehicle in which he was riding collided with a dump truck.

Buhriz and Baqouba are located northeast of Baghdad in violent Diyala province, where six U.S. soldiers were killed and four were wounded last week as they searched a booby-trapped house.

Those deaths came just days after the U.S. military launched a major operation to go after al-Qaida in Iraq and other extremists. While the operation is countrywide, parts of it are focusing on Diyala, which became an al-Qaida in Iraq stronghold after the terror group was pushed out of Baghdad and Anbar province west of the capital.

On Monday, the military said it was continuing to pursue al-Qaida in Iraq across Diyala and three other northern provinces.

The military also announced some results of the first week of the operation, saying U.S. and Iraqi forces killed 60 suspected extremists, detained 193 and found 79 weapons caches. Those caches included over 10,000 rounds of small arms ammunition, more than 2,000 heavy machine gun rounds, and over 4,000 pounds of homemade explosives.

While violence has declined over the past six months in Baghdad and many other places in Iraq, much of Diyala has remained a killing field. At least 273 civilians were slain in Diyala last month, compared to at least 213 in June, according to an Associated Press count. Over the same span, monthly civilian deaths in Baghdad dropped from at least 838 to at least 182.

Another bloody chapter in Iraq's history was put to rest Monday for several hundred families, when mourners in the northern Kurdish city of Irbil buried 365 victims of Saddam's 1980s Anfal campaign.

Anfal, which means "spoils of war," was the code-name for a 1986-88 crackdown that used poison gas and killed about 180,000 Kurds.

The 365 bodies had been recovered from two mass graves in the northern city of Mosul in 2004 and in the southeastern city of Samawah the following year. The bodies were then presented in court as evidence against three of Saddam's henchmen, including his cousin "Chemical Ali" al-Majid. All three were sentenced to die by hanging for crimes against humanity and genocide. They remain on death row.

In Kut, a predominantly Shiite city 100 miles southeast of Baghdad, police and a hospital official said U.S. troops opened fire at an intersection about 5 a.m., killing four people. They said the dead included a bus driver standing outside his vehicle and three construction workers waiting to be taken to their jobs. The police and hospital officials all spoke on condition of anonymity.

The U.S. military said American forces shot and killed a suspected criminal in Kut early Monday when two vehicles sped toward a joint U.S.-Iraqi patrol and did not obey warnings to stop.

It was not possible to reconcile the two versions.