BAGHDAD — Prime Minister Nouri al-Maliki on Monday urged other Arab countries to reopen their embassies in the capital as a show of support for his government as it cracks down on Shiite militias in Iraq.

Meanwhile, a police commander said six people died in clashes in Baghdad's embattled Shiite enclave of Sadr City. They included three policemen and three civilians, according to the officer who asked not to be named since he was not authorized to release the information.

The clashes between Shiite militiamen and government troops came after followers of hardline cleric Muqtada al-Sadr on Sunday raised the stakes in the showdown with al-Maliki's government, refusing to disband their Mahdi Army militia.

Al-Maliki, also a Shiite, has demanded that al-Sadr disband the Mahdi Army, the country's biggest Shiite militia, or warned his followers will not be allowed to run in provincial elections this fall.

The two sides have fought daily clashes in Baghdad since the prime minister launched an attack last month against the Mahdi Army in the southern port city of Basra. The militiamen have responded by shelling Baghdad's U.S.-protected Green Zone, which houses the U.S. Embassy and offices of the Iraqi government.

This included an attack on the zone on Sunday during a previously unannounced visit to Baghdad by Secretary of State Condoleezza Rice. During the talks, al-Maliki assured Rice that he will not back down in his confrontation with the militants.

There are fears that the continuing bloodshed in the capital could lead to the formal scrapping of a unilateral truce al-Sadr called last August — a move that American officials credit with helping dramatically reduce violence over the last year.

In the holy city of Najaf, a group of Sadrist lawmakers and officials issued a statement saying "we are ready for all possibilities" if the government continues its crackdown against the group.

U.S. military spokesman Lt. Col. Steve Stover said there had been sporadic "harassment fire" overnight in the sprawling Sadr City district where the Mahdi Army has its main stronghold.

He said that an armed drone fired a Hellfire missile at a group of gunmen late Sunday, killing all three.

"Iranian-backed special groups and other criminal elements who refuse to honor the rule of law are directly responsible for the current violence in Baghdad, as well as the deaths of countless innocent civilians," Stover said.

The U.S. military uses the term "special groups" criminals to refer to factions it says have refused to follow al-Sadr's cease-fire order and are being trained and armed by Iran. Tehran denies allegations it is fueling the violence in Iraq.

Meanwhile, al-Maliki urged Arab governments to cancel his country's debts.

"Iraq cannot alone shoulder the debt arising from the military adventures of (Saddam Hussein's) regime," al-Maliki told reporters Monday as he departed for Kuwait, where he will attend a conference involving Iraq's neighbors and world powers. They will discuss ways to help Iraq secure its borders and improve internal security and stability.

Most of Iraq's debt to the Paris Club of affluent creditor nations has been forgiven. According to the U.S. State Department, much of the remaining $67 billion in debt is owed to Saudi Arabia, Kuwait, the United Arab Emirates and Qatar.

Al-Maliki also urged other governments to open diplomatic missions in Baghdad. Most countries have been reluctant to do so due to safety concerns.

"I am a bewildered by the position of these nations. Do they want to support Iraq? Iraq has emerged from a crisis and needs to be supported," al-Maliki said.

Al-Maliki's comments come a day after Kuwait's foreign minister said the country was looking to open an embassy in Iraq for the first time since Saddam Hussein invaded his tiny oil-rich neighbor in 1990.

Elsewhere, a roadside bomb exploded on Monday next to a U.S. military convoy, causing casualties in Basra, a military statement said. It did not elaborate.

In Baqouba, a town 35 miles northeast of Baghdad, a woman wearing an explosive vest blew herself up at the headquarters of group of U.S.-allied Sunni fighters, said a police officer who received the initial report at the provincial headquarters.

The blast killed three people and wounded four, said the officer, who spoke on condition of anonymity because he was not authorized to speak to the media.

Police said the woman had asked to meet with members of the so-called awakening council because she was in dire need of financial assistance but she blew herself up when guards asked her to remove her all-encompassing black robe during a security search.

The armed groups, which the U.S. military credits with helping reduce violence in the area, have been coming under increasing attack from Sunni extremists.

A cameraman filming a flower nursery for a TV morning program also was wounded when gunmen in two cars also opened fire on civilians in eastern Baghdad, a colleague said.

Police said six people — including the cameraman Hameed Hashim and his driver — were wounded in the attack in the religiously mixed area of Zayouna.

A correspondent who was with Hashim escaped injury, according to the colleague, who declined to be identified because of security concerns.

The crew worked for the Biladi TV station, which is owned by former Prime Minister Ibrahim al-Jaafari.

Associated Press writers Qassim Abdul-Zahra in Kuwait City and Hamid Ahmed in Baghdad contributed to this report.