The opening marked a major milestone on the road to forming a new government in a country still beset by violence.

The parliament's 275 members, elected during Jan. 30 elections, convened in an auditorium amid tight security in the heavily guarded Green Zone with US helicopter gunships hovering overhead.

Minutes before convening, at least a half dozen explosions detonated a few hundred yards away. The US military said two mortar rounds landed inside the zone but caused no injuries.

The lawmakers opened with a reading of verses from the Quran. Iraqi Chief Justice Medhat al Mahmoud then administered the oath to the assembled deputies.

"It is a great day in Iraqi history that its elected representatives meet," said Fuad Masoum, a Kurdish delegate. "This day coincides with a painful memory that has many meanings. ... Today, on this occasion, we celebrate the inauguration of parliament after the fall of this regime."

Wednesday marked the anniversary of the Saddam Hussein-ordered chemical attack in 1988 on the northern Kurdish town of Halabja, an attack that killed 5,000 people.

Iraqi leaders have not yet agreed on a coalition government, and the leader of the Shiite-dominated United Iraqi Alliance, cleric Abdel Aziz al-Hakim, said his alliance hoped to "form a government whose motto is to serve the Iraqi people, a government of national unity and reconciliation."

"A government that can root out violence and set a trial for Saddam and the elements of his regime," Hakim said in a speech that wove in and out of prayer. He said a government led by the alliance would also try "to achieve the independence of Iraq and put an end to the role of multinational forces in Iraq."

Jalal Talabani, the Kurdish leader who will probably become Iraq's next president, said deputies "all have a duty to achieve real national unity."

"Iraq is facing tough times due to the continuation of criminal terror crimes," he said. "al-Qaeda is waging a war of extermination on Kurds and Shias."

The alliance and a Kurdish coalition agreed last week to form a coalition government with Shiite politician Ibrahim al-Jaafari as prime minister. In return, Talabani will become Iraq's first Kurdish president, though the presidency is a largely ceremonial post.