BAGHDAD, Iraq (AP) – A suicide bomber killed nine people at the party headquarters of the Iraqi president Tuesday, and fierce gunbattles between supporters of an anti-American Shiite cleric and Iraqi forces left at least six people dead, officials said.

The suicide bomber blew up his bomb-rigged truck in the parking lot of the headquarters of Iraqi President Jalal Talabani’s party, the Patriotic Union of Kurdistan, in the northern city of Mosul.

At least five civilians and four Kurdish security personnel, known as Peshmergas, were killed, police Col. Abdul-Kareem Ahmed al-Jibouri said. He said 41 people were injured in the blast, which damaged the one-story office building and set 17 cars on fire.

In the southern city of Karbala, Shiite gunmen and security forces exchanged gunfire for several hours Tuesday near one of Iraq’s holiest shrines containing the mausoleum of Hussein, a revered figure in Shiite history.

The fighting in the relatively peaceful Shiite-dominated south presents a new headache for the unity government of Iraq and U.S. troops trying to control a Sunni insurgency and sectarian fighting between Shiites and Sunnis.

The violence, which has occurred mostly in the predominantly Sunni provinces in and around Baghdad, has surged since a Feb. 22 bombing of a Shiite mosque. The sectarian violence is claiming more than 1,000 lives every month around Baghdad alone.

A Karbala Health Directorate official said six people were killed and five people were wounded in the clashes in Karbala. The official spoke on condition of anonymity because he was not authorized to speak to journalists.

The fighting spread over at least five neighborhoods of Karbala around the office of Mahmoud al-Hassani, a cleric who came into prominence after the ouster of Saddam Hussein in 2003.

The fiercely anti-American al-Hassani is believed to have several thousand followers. His whereabouts have remained unknown since his office was raided in 2004 by Polish soldiers, part of the U.S.-led coalition force.

But his followers were out in force Tuesday, wielding AK-47 rifles, heavy machine guns and rocket-propelled grenades that they fired at army patrols before running away. Soldiers fired at groups of gunmen roaming the streets.

The trouble started after Iraqi soldiers raided al-Hassani’s office before dawn, apparently in search of weapons. Ahmed al-Ghazali, an aide to the cleric, said the raid resulted because al-Hassani’s supporters taking over a field behind the building for security reasons.

The raid set off the gunbattles, which raged for several hours despite an indefinite curfew in Karbala, 50 miles south of Baghdad.

Meanwhile, the U.S. military acknowledged Tuesday that car bombs were responsible _ at least partly _ for the explosions Sunday night in the Baghdad neighborhood of Zafraniyah that killed dozens of people.

On Monday, the U.S. military spokesman, Maj. Gen. William B. Caldwell, had said the destruction in the predominantly Shiite area was caused by a gas line explosion and there was no evidence of car bombs or rockets. However, Iraqi officials and residents insisted it was a combination of bombs and rocket attacks launched from a Sunni neighborhood.

A U.S. military statement said Tuesday that about 63 Iraqis were killed and 140 wounded when two car bombs “detonated in the vicinity of a building, causing a gas explosion.” The combination of the explosions “resulted in the collapse of a residential building,” it said.

The statement said two more car bombs later went off within a mile of the first blast. Four buildings and 20 shops were destroyed, it said.