After five months of often bitter wrangling over Cabinet posts, Iraq's unity government took office Saturday and vowed to fight the insurgency, restore stability and set the stage for the eventual withdrawal of U.S. and other foreign troops.

The new permanent government resulting from December's elections in which 12 million Iraqis participated has been portrayed by Western officials as the best hope for changing the dynamics of violence in Iraq. But it must expand control and persuade insurgents, assassins and militias to stand down, with no guarantee of success.

As the Cabinet was sworn in, at least 33 people were killed in a series of attacks across Iraq, and police found the bodies of 22 Iraqis who apparently had been kidnapped and tortured by death squads that plague the capital and other areas.

Prime Minister Nouri al-Maliki and the others on the 40-member Cabinet took the oath of office inside the heavily fortified Green Zone in central Baghdad, where American and Iraqi troops provide security from the turmoil sweeping the country.

After a two-hour delay, reportedly because of last-minute wrangling over some Cabinet posts, legislators dressed in suits or traditional Arab robes slowly filed into the parliament chamber. Outgoing members of the interim legislature greeted each other with kisses to the cheeks.

The vote of approval went quickly, with parliament members elected in Dec. 15 elections waving raised hands to ratify al-Maliki's nominees one by one.

Al-Maliki, a Shiite Muslim who spent years in exile in Syria during Saddam Hussein's regime, promised that restoring security would be his top priority.

"The first challenge we face is security and how to deal with the terrorist killers who are destroying the country and shedding the blood of the Iraqi people," he said. "Those people should know that this government is designed in a way to effectively face this challenge."

He outlined a 34-point plan to bring security, implement the rule of law and restore basic services like electricity — now available for only four hours a day in the capital.

In a sign of the divisions that held up forming the government, al-Maliki could not work out an agreement on the Cabinet's three posts responsible for security and had to appoint himself and two deputy prime ministers to temporarily hold those positions.

Al-Maliki, who has a reputation as a hard-liner, was chosen by the dominant Shiite bloc after Sunni and Kurdish parties refused to accept Prime Minister Ibrahim al-Jaafari for a second term as head of government. U.S. officials also opposed al-Jaafari, viewing him as ineffectual. Nevertheless, Al-Maliki, 55, is politically close to al-Jaafari and is largely untested as an administrator.

President Bush, who is facing rising criticism at home over Iraq, welcomed the new Cabinet and promised continued U.S. help.

"Iraq's new leaders know the period ahead will be filled with great challenge," Bush said in a statement. "But they also know that they — and their great country — will not face them alone. The United States and freedom-loving nations around the world will stand with Iraq as it takes its place among the world's democracies and as an ally in the war on terror."

U.S. Ambassador Zalmay Khalilzad repeated U.S. cautions against expectations of a quick pullout of the 132,000-strong American military contingent. But, he added, "strategically, we're going to be moving in the direction of downsizing our forces."

Hussain al-Shahristani, the Shiite Muslim chosen as oil minister, promised to increase oil production and give all Iraqis a share.

"For every Iraqi, a share in the oil wealth," al-Shahristani said.

As for the three unfilled posts, Al-Maliki said he would be acting interior minister for now, and he tapped his Sunni Arab deputy prime minister, Salam Zikam al-Zubaie, as temporary defense minister. Deputy Prime Minister Barham Saleh, a Kurd, will be acting minister of state for national security.

The new prime minister hopes to fill the jobs with politicians who are independent and have no affiliation with any of Iraq's sectarian militias, which are blamed for the sharp rise in Shiite-Sunni bloodshed that has raised fears of civil war.

The greatest drama of the day underlined the difficulties al-Maliki faces in calming those sectarian passions.

Sunni Arab lawmaker Saleh al-Mutlaq demanded the government's swearing-in be postponed until the security ministries were allotted, delivering an angry speech that lasted nearly 10 minutes before the microphone was taken away. Then he and about 10 other Sunni deputies from his Arab nationalist faction stalked out in protest.

Much more than restoring security is at stake for the government and the United States, which designed and engineered much of the transition to democracy in the three years since it invaded Iraq and set the stage for al-Maliki's coalition of Shiites, Sunni Arabs and Kurds.

Many analysts fear the country's violence has assumed some characteristics of an irregular civil war, including targeted assassinations, sectarian bombings and armed groups seeking power and attacking the central government and its employees.

Many of Iraq's insurgent groups are led by Sunni Arabs, and a goal of the new government is to win the support of that formerly dominant minority and to recruit as many of them as possible into Iraq's security forces — especially in insurgent strongholds like western Anbar province.

One of Saturday's attacks, a suicide car bombing at a police station that killed at least five people and wounded 10, took place in Anbar city of Qaim.

In the day's deadliest assault, 19 people died when a bomb hidden in a paper bag exploded in Baghdad's Sadr City district next to a line of day laborers waiting for work.

Sadr City is the stronghold of the radical Shiite cleric Muqtada al-Sadr, a foe of the U.S. presence who operates a powerful militia outside the government's control. Al-Maliki hopes to absorb such militias into the Iraqi army and police as a way of reducing violence.

Elsewhere, a suicide bomber killed three civilians in the northern city of Mosul, gunmen killed an Iraqi military officer, his wife and son in Baqouba, a mortar shell exploded at a Sunni mosque and killed two people in the capital's Jihad neighborhood, and two blacksmiths were shot to death in central Baghdad.

Police also found the bodies of 22 people who apparently had been kidnapped and tortured, six in Baghdad, 15 in the southern city of Musayyib and one in nearby Hafriya. All appeared to be victims of death squads that have killed hundreds in sectarian violence, personal vendettas and kidnappings for ransom.