Iraq's new Prime Minister Nouri Maliki has vowed that he will use "maximum force" against terrorism, while also promoting national reconciliation.
At least 17 people died in Sunday's attacks
Mr Maliki was speaking as the Iraqi cabinet met for the first time since it was approved by parliament on Saturday.
His comments came as the Iraqi capital was hit by a series of bomb attacks.
In the deadliest incident a suicide bomber killed 13 people and injured 18 in an attack on a crowded restaurant in Baghdad's central Karada district.
The attack on the restaurant near a police station took place at 1320 local time (0920 GMT), police said.
Police said they believed the bomber was wearing an explosives vest. The dead included several police officers.
In other Sunday's attacks in Baghdad:
- three people are killed and at least 17 are injured in a roadside bomb blast in a crowded market in the eastern New Baghdad district
- at least one person is killed and 15 are injured in a car bomb attack in the western Shula district
- five people are injured when a bomb - targeting a police patrol - goes off in the south-western Saydiya district. The bomb missed its intended target.
The BBC's Jim Muir in Baghdad says that the violence highlights the challenge facing Iraq's new government.
Mr Maliki vowed to crack down on the militias blamed for much of Iraq's violence.
"We will use maximum force against terrorism, but we also need a national initiative," Mr Maliki said.
"Weapons should only be allowed in the hands of the government. Militias, death squads, terrorism, killings and assassinations are not normal and we should put an end to the militias," he said.
But Mr Maliki also stressed the need for national reconciliation and other measures to restore normality.
The new Iraqi cabinet unites members of the major Shia, Kurd and Sunni parties, but three crucial ministries - national security, interior and defence - have still to be agreed.
Mr Maliki said he hoped ministers to head these departments would be agreed within the next two or three days.
He also outlined plans for a special force to protect Baghdad.
Responding to the new government's taking office, US President George W Bush said it marked a "a new day for the millions of Iraqis who want to live in freedom".
"I assured them that the United States will continue to assist the Iraqis in the formation of a free country," Mr Bush said after he had spoken by telephone with Iraq's leaders.
UK Foreign Secretary Margaret Beckett said the formation of the new Iraqi government was an encouraging sign, adding that any decision to hand over some key responsibilities to Iraqi troops would be made on "a case-by-case basis".
"We are making some progress in both training and putting into place an Iraqi army, Iraqi police force who will gradually, increasingly take over some of these responsibilities," Ms Becket told the BBC.
"But I would envisage that even when responsibility is handed over to those Iraqi forces, they'll probably want some outside support for quite a while," she said.