The U.S. military said Saturday it has captured two senior terrorists linked to Iraq's most feared Islamic militant group as police uncovered more bodies under the rubble a day after a homicide bomber blew up a gas tanker in an upscale Baghdad (search) district.

The two detainees linked to Jordanian terrorist Abu Musab al-Zarqawi's (search) Al Qaeda in Iraq network were identified as Saleh Arugayan Kahlil and Bassim Mohammad Hazeem.

"Both of these individuals were cell leaders for a local Zarqawi-affiliated terrorist group that is operating" in the western province of Anbar that include the cities of Ramadi and Fallujah, U.S. Marines said in a statement.

Al-Zarqawi's group recently changed its name to Al Qaeda in Iraq and pledged allegiance to Usama bin Laden's Al Qaeda network. It has claimed responsibility for numerous deadly attacks against U.S. troops and government forces.

No group has yet claimed responsibility for the gas truck explosion Friday night in the upscale Mansour district near the Libyan and Moroccan embassies, which killed at least nine people and demolished several houses. Police said it was a homicide attack.

Rescuers on Saturday uncovered seven more bodies under the rubble of one of the shattered housed. At least 14 people were seriously wounded by the blast which struck just hours after U.S. Defense Secretary Donald H. Rumsfeld left the capital following an unannounced one-day visit to Iraq.

A witness of the blast, who identified himself only as Abdel Imam, said that the gas truck sped into the Mansour districts with lights turned off moments before its driver triggered the detonation.

There were no members of the multinational forces among the casualties. There were no injuries inside the embassies.

The Marine statement announcing the arrest of the suspected extremists said al-Zarqawi's cell "kidnapped and executed 11 Iraqi National Guardsmen," carried out car bombings and other attacks in the Ramadi area and "smuggled foreign terrorists into the country."

"This group is responsible for intimidating, attacking and murdering innocent Iraqi civilians, Iraqi police and security forces, and business and political leaders throughout the Anbar province," the statement said.

Violence has escalated across Iraq in the run-up to national elections scheduled for Jan. 30.

While majority Shiites have embraced the polls as a chance to assert their numerical strength, radical elements within the minority Sunni community are leading the campaign to prevent the vote.

In other violence Saturday, a car bomb exploded as a U.S. military convoy was passing through the southern town of Ein al-Nus, killing three Iraqis and wounding two, police said.

Gunmen shot dead Hasan Abdul-Ghani al-Rubaei, a professor at Baghdad University's medical school, as he drove his car along the dangerous Haifa street where militants often launch attacks.

And a roadside bomb exploded Saturday near the car of the governor of eastern Diyala province, wounding four of his guards, officials said.

Governor Abdullah Rashid al-Jbouri was unharmed in by the blast in the town of Khan Bani Saad, halfway between Baqouba and Baghdad, said Dr. Abdullah Mohammed of the Baqouba General Hospital.

Meanwhile, Iraqi police have arrested a group of six men suspected to have organized last week's explosions in the Shiite holy city of Najaf that killed more than 50 people. Governor Adnan al-Zurufi said the six belonged to a "terrorist cell." He did not release their identities or nationalities.

More displaced residents of the battered city of Fallujah returned to inspect their devastated homes Saturday, the third day that authorities have allowed some citizens back into the city.

Repatriating the tens of thousands of people who fled Fallujah before the U.S. assault in November is a key step in the attempt to restore stability in the city ahead of January elections.

Some complained the strict security measures imposed by the government and U.S. troops on the returning refugees.

"Every two hours, they are letting one car pass through the checkpoint," complained a man who identified himself only as Hassan. "And there are so many checkpoints and measures before we can get into the city, such as sniffing dogs and mirrors being put under our cars."

On Thursday and Friday, a total 1,404 residents returned to their homes in the Andalus district of Fallujah under the supervision of government and U.S. forces, a Marine statement said.