Iraq's prime minister met Sunday with the Sunni Arab vice president to discuss reintegrating Sunni political parties into the Shiite-dominated government as militants fired a salvo of rockets or motars at the heavily guarded Green Zone.

At least eight rounds slammed into the section of Baghdad that houses the Iraqi government and U.S. Embassy, said a police official who asked not to be named because he was not authorized to speak to the media.

Sirens could be heard from the area and loudspeakers warned residents to take cover. There was no immediate word on casualties or damage.

The militants apparently were taking advantage of a sandstorm that blanketed the Iraqi capital Sunday and grounded U.S. helicopters and drones that normally track their activities.

Meanwhile, the meeting between Prime Minister Nouri al-Maliki and Tariq al-Hashemi came a day after the Sunni leader said the return of his boycotting political bloc to the Cabinet was a priority.

The two men discussed "the future of the political process and the rebuilding of a national and unified government," according to a statement from the presidency office.

On Saturday, al-Hashemi said the government needs to reconcile quickly to "save Iraq."

His comments were the latest to signal readiness by the Sunni National Accordance Front to rejoin the government after an absence of nearly nine months. The group quit the government in protest over what they described as its anti-Sunni bias.

But Sunni officials have said internal power struggles within the Front over who should be appointed to which posts have delayed a formal decision.

Al-Hashemi has been one of al-Maliki's most bitter critics, accusing him of sectarian favoritism, while the prime minister has complained that the vice president is blocking key legislation.

But al-Hashemi and other Sunni leaders apparently have been swayed by al-Maliki's crackdown against Shiite militias that began late last month and focused on the feared Mahdi Army of anti-U.S. cleric Muqtada al-Sadr. Al-Maliki also has threatened to politically isolate al-Sadr if the Mahdi Army is not disbanded.

Sporadic clashes continued Sunday in the Mahdi Army stronghold of Sadr City, a sprawling district in northeastern Baghdad with 2.5 million people. Fighting in the district has been ongoing since al-Maliki first launched his campaign a month ago against militias in the southern city of Basra.

An Iraqi military spokesman said that over the past month, militants had fired a total of 712 missiles and mortar rounds inside Baghdad.

"They were all Iranian-made brought into Iraq in many ways," Brig. Gen. Qassim al-Moussawi told reporters. He did not elaborate on how the security forces had determined the origin of the exploded munitions.

The Green Zone has been regularly shelled since March, and two American soldiers were killed in the bombardment earlier this month.

Iraqi police said two people were killed and 12 injured in Sadr City in exchanges of fire between joint Iraqi-American forces and fighters of the Mahdi army.

Four of the injured in the clashes early Sunday were young children, said an officer who declined to identify himself because he was not authorized to speak to the media.

The police officer said U.S. Apache helicopters were circling the area and providing support to the government forces.

But a U.S. military statement said an unmanned drone had killed a total of five militants using Hellfire missiles in three separate engagements.

A delegation of about 40 lawmakers from various Sunni, Kurd, Turkomen and Shiite parliamentary parties visited Sadr City Sunday and urged the government to end the military campaign there.

In the southern suburb of Maalif, five people died and 14 were wounded in a clash between Shiite militiamen and Iraqi and American forces, said a local police official who spoke on condition of anonymity because he was not authorized to give the information to the media. The U.S. military denied that its forces were engaged there.

Associated Press Television News footage from the scene showed a minibus riddled with bullets and a pool of blood in another minibus.

Elsewhere in Baghdad, a suicide car bomber blew himself up at a security checkpoint in the eastern neighborhood of Zayouna killing three people and injuring nine, a police officer said, speaking on condition of anonymity because he is not authorized to release the information.

U.S. spokesman Rear Adm. Patrick Driscoll said a series of recent car bombings and suicide attacks showed that Al Qaeda in Iraq remains "a very lethal threat" and said the military would continue to pursue the insurgents "with great intensity."