Also, the U.S. military said a soldier was killed by a roadside bomb while on patrol in western Iraq.
The soldier, assigned to the 56th Brigade Combat Team, was taken to a U.S. military hospital where he died of his wounds Saturday night. The attack occurred near Al Asad Air Base in a volatile insurgent region near Syria.
The death raises to at least 1,899 members of the U.S. military who have been killed since the beginning of the Iraq war in March 2003, according to an Associated Press count.
"The terrorists have launched a war of aggression against all Iraqis (but) we are up to it," Hussain al-Shahristani, the National Assembly's deputy speaker, said Sunday as lawmakers held a minute of silence for Faris Nasir Hussein, a member of the Patriotic Union of Kurdistan party who was killed in ambush late Saturday about 50 miles north of Baghdad.
Hussein's brother and the driver of the car also died. Another legislator, who was also in the convoy heading from Kurdistan for a session of parliament in Baghdad, was wounded in the attack.
The attack on the lawmakers came after four days of bloodshed in Baghdad and elsewhere in Iraq in which more than 250 people perished.
The violence coincided with a declaration on Wednesday of all-out war on the country's Shiite majority by the al Qaeda in Iraq militant group.
Shiites have suffered the brunt of a massive campaign of bombing and shooting attacks. But the indiscriminate bombings prompted Islamic clerics from both the Sunni and Shiite sects to call for an end to the killing of innocent people.
Meanwhile, Parliament on Sunday signed off on revisions to the country's draft constitution.
Al-Shahristani said the new basic law was given to the United Nations, which will print 5 million copies and distribute them to Iraqis before the Oct. 15 national referendum on the charter.
The original draft was not voted on by the parliament and al-Shahristani did not call for legislative approval on the amendments.
The changes to the document included an apparent bow to demands from the Arab League that the Iraq be described as a founding member of the pan-Arab organization, and that it was "committed to its charter." Other changes included giving the federal government responsibility for the management of water resources and the creation of two deputy prime minister positions.
Iraq's Sunni minority, which held sway during the rule of Saddam Hussein, has complained the constitution favors the Shiite majority and Kurds, who dominated the committee that wrote the document.
In other developments:
The Iraqi army said a total of 157 insurgents had been killed and 440 captured during the 10-day offensive. Army spokesman Maj. Gen. Abdul Aziz Mohamed Jassim, said nine Iraqi soldiers and six policemen died.