The Iraqi army has reportedly killed 30 militants and arrested several others, including a number of Sudanese nationals, in a gun battle in Baghdad.
Mr Maliki promised tough measures against sectarian gunmen
State TV said the firefight took place near Haifa Street, a Sunni district which housed top officials during Saddam Hussein's regime.
The engagement in the centre of the city is believed to mark the start of a new security drive in the capital.
Iraq's PM has pledged to take action against all illegal armed groups.
Earlier, 71 bodies, apparently the victims of sectarian violence, were found dumped at locations in Baghdad.
Twenty-seven were left near a Sunni shrine in the central Sheikh Marouf area. Police said they were the victims of execution-style killings.
Elsewhere, at least two people died when a parked car exploded near a fuel station in the Doura district of the city.
In another incident, a car bomb was detonated beside the motorcade of a senior police official, Major-General Ali Yasser. He survived, but a bystander was killed.
Meanwhile, the US military said its forces had killed four suspected insurgents and detained a fifth in the city. It said all five had been armed, and that they were suspected of involvement in making roadside bombs.
Prime Minister Nouri Maliki said the new security plan would be implemented by the Iraqi army, supported by US forces.
Mr Maliki said the new security plan would create inconveniences for the people of Baghdad, but it was for their own good.
Bush may send thousands more US troops to Baghdad
In a speech to mark Iraqi Army Day, he said: "We will rely on our armed forces to forcefully implement the plan and the multinational forces will support our forces."
He added: "There will be no refuge from this plan for anyone who is operating beyond the law, regardless of their sect or their political affiliation."
It comes only days before President George W Bush is due to outline his new strategy for Iraq.
He is widely expected to send thousands more troops to Iraq, despite calls from the new Democratic Party leaders of Congress for the US to begin withdrawing its forces.
Mr Maliki also said his government could review relations with any country which criticised the execution of ex-leader Saddam Hussein.
Mr Maliki said the hanging was a "domestic affair" for the benefit of Iraq's unity, adding that the former president had received a fair trial.
Mobile phone images showing Saddam Hussein being taunted appeared on the internet days after the execution.
On Saturday, new UN Secretary-General Ban Ki-moon urged Iraq not to execute two of Saddam Hussein's co-defendants, Barzan Ibrahim al-Tikriti and former chief judge Awad al-Bandar.
Mr Ban was criticised this week for not stating the UN's opposition to the death penalty over Saddam Hussein's hanging.
Several Sunni Arab countries criticised the hanging as sectarian.
Egyptian President Hosni Mubarak said it had turned the former leader into a martyr.