BAGHDAD, Iraq (AP) _ Gunmen in Interior Ministry commando uniforms stormed the offices of a private security company and kidnapped as many as 50 employees Wednesday, while U.S. and Iraqi patrols reported the discovery of 24 shot or garroted bodies in the capital.

Iraq's Shiite vice president, meanwhile, signed a presidential decree calling parliament into session, breaking a major logjam that had delayed the creation of a unity government that U.S. officials hope can curb the unrelenting violence so their forces can start going home in the summer.

``He signed the decree today. I expect the first session to be held on Sunday or by the end of next week at the latest,'' said Nadim al-Jabiri, head of one of seven Shiite parties that make up the United Iraqi Alliance, the largest bloc in parliament.

Unidentified attackers hit the al-Rawafid Security Co. at 4:30 p.m. and forced the workers into seven vehicles, including several white SUVs, said Interior Ministry Maj. Falah al-Mohammedawi. The victims, including bodyguards, drivers, computer technicians and other employees, did not resist because they assumed their abductors were police special forces working for the Interior Ministry, al-Mohammedawi said.

Interior Ministry Undersecretary Maj. Gen. Ahmed al-Khefaji denied any involvement by his department, saying: ``It is a terrorist act.''

Members of the Sunni Arab minority who dominated under ousted leader Saddam Hussein accuse the Shiite-led security forces of repeated abductions and killings under the cover of fighting the Sunni-driven insurgency. Many of Al-Rawafid employees are former members of Saddam's armed forces.

The company is one of dozens providing protection for businesses and other clients in the violence-plagued country. One of its main clients is Iraqna, a cell phone firm owned by Egyptian-giant Orascom. Its offices are in Zayouna, a volatile mixed Sunni-Shiite neighborhood in east Baghdad.

Bombings, gunfire and other violence claimed at least 12 other lives, Iraqi police and the U.S. military said Wednesday. Among the reported deaths was a U.S. soldier who was killed by a roadside bomb Tuesday near the northwestern city of Tal Afar. Four other soldiers were wounded in the attack, the military said.

An American military patrol found 18 of the bodies _ all males _ in an abandoned minibus Tuesday night on a road between two notorious mostly Sunni west Baghdad neighborhoods.

The bodies were brought to Yarmouk Hospital and lined up on stretchers for identification. Most had bruising indicating they were strangled and two were shot, said Dr. Muhanad Jawad. Police believed at least two of the men were foreign Arabs.

Police found the bodies of six more men _ four of them strangled and two shot _ discarded in other parts of the city.

The gruesome discoveries followed a surge of sectarian violence unleashed by the Feb. 22 bombing of a sacred Shiite shrine in the central city of Samarra and reprisal attacks against Sunni mosques and clerics. Sectarian killing has diminished in recent days, but other attacks have increased, the Defense Ministry said.

A string of explosions Wednesday killed at least six people _ including two young boys _ in the capital, police said.

One bomb hidden under a parked car detonated as police from the interior minister's protection force were driving through Baghdad, killing two officers and injuring another, police said. Four bystanders were injured. The minister was not in the convoy at the time.

Another roadside bomb hit a police patrol in northern Baghdad, killing two officers and injuring four others, police said.

A third one missed an American convoy on the northern outskirts of Baghdad and killed two Iraqi boys _ about 10 or 11 years old _ who were selling gasoline by the roadside, police said.

A car bomb targeting another U.S. convoy in north Baghdad injured five bystanders, police said. There was no immediate word on American casualties.

An Iraqi patrol saw four gunmen pull a man from the trunk of a car and shoot him to death in west Baghdad, police reported. They said the patrol tried to intercede, but the gunmen fired at them and fled.

More gunmen pulled over a school bus carrying about 25 high school girls and shot the driver in front of his terrified passengers. The wounded driver was hospitalized, police said.

Vice President Adil Abdul-Mahdi's signature Wednesday on an executive order opened the way for the much-delayed first session of the parliament elected Dec. 15 _ and also signaled fundamental disagreement within the once-unified majority Shiite ranks.

The constitution dictates that the first meeting be held no later than Sunday, but negotiations were still under way on a specific date, said al-Jabiri, the Shiite official.

The first session had been delayed by weeks of intense political infighting and reached an impasse after Abdul-Mahdi refused to sign President Jalal Talabani's decree Monday.

The dispute centers around Shiite Prime Minister Ibrahim al-Jaafari's bid for a second term, which is opposed by a coalition of Sunni Arab, Kurdish and secular Shiite politicians.

Talabani, a Kurd, has openly challenged al-Jaafari's candidacy on grounds he is too divisive and would be unable to form a government representing all Iraq's religious and ethnic factions. There was also great unease over al-Jaafari's close ties to radical anti-American cleric Muqtada al-Sadr

The Shiite Alliance is itself divided over al-Jaafari's candidacy. He defeated Abdul-Mahdi by a single vote in a Shiite caucus last month, due in large part to al-Sadr's support.

Talabani had hoped to bring the dispute to a head by convening parliament Sunday. Under the constitution, parliament is supposed to elect a new president within 15 days of its first meeting. It then has 15 more days to approve the prime minister, and 30 days after that to vote on his Cabinet.

To convene the session, Talabani needed the approval of his two vice presidents. Ghazi al-Yawer, a Sunni who is out of the country, gave Talabani power of attorney Monday to sign on his behalf. Abdul-Mahdi initially declined, but reversed his position Wednesday.

Another key Shiite political figure, speaking anonymously because of the sensitive nature of the information, said Abdul-Mahdi had acquiesced after U.S. Ambassador Zalmay Khalilzad sought the intervention of powerful Shiite leader Abdul-Aziz al-Hakim in breaking the stalemate during a meeting Tuesday.

Abdul-Mahdi heads the Shiite parliamentary bloc loyal to al-Hakim, who leads the Supreme Council for the Islamic Revolution in Iraq.

Al-Jabiri, however, said the decision to sign was taken on advice Wednesday from Iraq's Federal Court, which said parliament could be convened through an alternative process if Abdul-Mahdi continued to hold out.

As political negotiations progressed, the violence raged on.

Gunmen shot and killed a Sunni imam, Sadi Mahmoud, on his way home from a mosque in west Baghdad, police said.

A former brigadier in Saddam's army was shot and killed in west Baghdad, police said. Gunmen also attacked the convoy of Interior Ministry Undersecretary Hekmet Moussa in west Baghdad, killing two bodyguards and injuring two others, police said. Moussa was not in the convoy.

A bomb exploded at the Basra headquarters of Iraq's South Oil Co., causing minor damage but no casualties. Crude production and exports were not affected, said Jabar Luaibi, the company's director general.

Also Wednesday, an Iraqi civilian was killed in a collision with a U.S. Bradley Fighting vehicle after failing to heed warnings to stop, the military said.

The death of the U.S. soldier that was reported Wednesday brought to at least 2,302 the number of U.S. military members who have died since the beginning of the war in March 2003, according to an Associated Press count. The figure includes seven military civilians.