Iraq's new parliament was sworn in Thursday, with parties still deadlocked over the next government, vehicles banned from Baghdad's streets to prevent car bombings and the country under the shadow of a feared civil war.

The long-expected first session, which took place within days of the third anniversary of the U.S.-led invasion, lasted just over 30 minutes and was adjourned indefinitely because the legislature still has no speaker.

Adnan Pachachi, the senior politician who administered the oath in the absence of a speaker, spoke of a country in crisis.

"We have to prove to the world that a civil war is not and will not take place among our people," Pachachi told lawmakers. "The danger is still looming and the enemies are ready for us because they do not like to see a united, strong, stable Iraq."

As Pachachi spoke, he was interrupted from the floor by senior Shiite leader Abdul-Aziz al-Hakim, who said the remarks were inappropriate because of their political nature.

Even the oath was a source of disagreement, with the head of the committee that drafted the country's new constitution, Humam Hammoudi, protesting that lawmakers had strayed from the text. After brief consultations, judicial officials agreed the wording was acceptable.

Meanwhile, a top Iranian official said his country was ready to open direct talks with the United States over Iraq, marking a major shift in foreign policy a day after al-Hakim called for such talks.

Ali Larijani, Iran's top nuclear negotiator and secretary of the country's Supreme National Security Council, told reporters that any talks between the United States and Iran would deal only with Iraqi issues.

"To resolve Iraqi issues and help establishment of an independent and free government in Iraq, we agree to (talks with the United States)," Larijani said after a closed meeting of the parliament Thursday.

Larijani said the U.S. Ambassador to Iraq, Zalmay Khalilzad, also had invited Iran for talks on Iraq.

Washington, which repeatedly has accused Iran of meddling in Iraq's affairs and of sending weapons and men to help insurgents in Iraq, had no immediate response.

The statement marked the first time since the 1979 Islamic Revolution that Iran had officially called for dialogue with the United States.

A pianist played as representatives of Iraq's main ethnic and religious blocs — many in traditional Arab and Kurdish dress — filed into a convention center behind the concrete blast walls of the heavily fortified Green Zone for parliament's first meeting.

Hours after the session adjourned, two mortar shells were fired into the Green Zone, al-Mohammedawi said. No casualties were reported.

The inaugural session started the clock on a 60-day period in which parliament must elect a president and approve a prime minister and Cabinet.

Acting Prime Minister Ibrahim al-Jaafari was optimistic. "If politicians work seriously, we can have a government within a month," he said.

Al-Jaafari's candidacy for a second term as prime minister is at the center of the political logjam that delayed parliament's first session for more than a month after the results of Dec. 15 elections were approved.

There was little sign of progress after a second full day of meetings Wednesday among leaders of the major political blocs. The U.S. ambassador brokered the sessions.

"I expect that there still will be difficulties over choosing the prime minister," said Mahmoud Othman, a Kurdish politician who attended Wednesday's session.

Under the constitution, the largest parliamentary bloc, controlled by Shiites, has the right to nominate the prime minister. Al-Jaafari won the Shiite nomination by a single vote last month.

Politicians involved in the negotiations have said part of the Shiite bloc, those aligned with al-Hakim, would like to see al-Jaafari ousted but fear the consequences, given his backing from radical cleric Muqtada al-Sadr and al-Sadr's thousands-strong Mahdi Army.

Sunni, Kurdish and some secular Shiites argue al-Jaafari is too divisive and accuse him of not doing enough to contain waves of revenge killing after bombers destroyed an important Shiite shrine on Feb. 22 and ripped apart teeming markets in an al-Sadr stronghold in Baghdad on Sunday.

Police discovered 29 more bodies discarded in various parts of Baghdad late Wednesday and Thursday. The victims were all men, some with their hands bound, who had been shot execution-style and dumped in both Shiite and Sunni Muslim neighborhoods, Interior Ministry official Lt. Col. Falah al-Mohammedawi said.

North of the capital, a roadside bomb exploded near a girl's primary school near Baqouba, killing three students ages 12 to 13 and wounding two others, police said.

Another bomb missed a U.S. patrol in Mosul, killing one civilian and wounding three others, police said. Four more people were killed in a drive-by shooting in the northern city.

In Ramadi, residents picked through the rubble of a home they said was destroyed in a U.S. raid. Residents have reported repeated clashes in the city in an insurgent-plagued area west of Baghdad.

Recent AP Television News video showed a gunbattle in which a gasoline truck was set on fire, and at a separate location the killing of an unidentified man with heavy gunfire audible in the background. The U.S. military has not responded to repeated requests for information.

Parliament's first meeting coincided with the 18th anniversary of a poison gas attack by Saddam Hussein's army on the northern city of Halabja.

Nearly 2,000 Kurdish demonstrators, angry over what they see as the regional government's failure to rebuild the area, went on a rampage Thursday and badly damaged a monument to the 5,000 residents killed. Police fired live ammunition into the air, killing one person and wounding at least eight.

Saddam ordered the poison gas attack as part of a scorched-earth campaign to crush a Kurdish rebellion in northern Iraq.

President Jalal Talabani, a former Kurdish guerrilla leader, said Thursday, "the Halabja anniversary inspires us to continue our struggle against dictatorship."

Looking ahead to concerns about violence ahead of a major Shiite holiday Monday, authorities in Karbala imposed a six-day driving ban starting Thursday in a bid to protect pilgrims this year.

Monday also marks the third anniversary since the U.S.-led invasion of Iraq on March 20, 2003.