BAGHDAD -- Gunmen loyal to radical Shi'ite cleric Moqtada al-Sadr ambushed an Iraqi patrol in an eastern Baghdad slum yesterday, and US forces joined the 90-minute battle, killing as many as eight attackers in the first significant violence in the neighborhood in nearly a year.
Elsewhere in Baghdad, armed men escaped with $850,000 after killing two guards in an armored-car robbery, and a suicide car bomber slammed into a convoy carrying Interior Ministry commandos, killing seven of them and two civilians.
South of the capital, two separate bicycle bombings in town markets killed at least seven people and wounded dozens.
The resurgence of violence in the impoverished Sadr City area began about 1:30 a.m. when an Iraqi patrol searching for three insurgents came under attack. US forces in the neighborhood joined the battle and reported killing between five and eight of the attackers. Iraqi police said eight were killed.
''I am concerned about the events early this morning, but I do not believe this action reflects a pattern of change leading to more violence," said Colonel Joseph DiSalvo, commander of US forces in east Baghdad.
Sadr's militia, the Mahdi Army, was a repeated problem American forces until a truce was negotiated about a year ago that allowed some US troops to pull out of Sadr City to join the November assault on the insurgent stronghold of Fallujah, west of the capital. Before the truce, Sadr's forces had led unsuccessful but bloody uprisings against coalition forces in Kut and the holy cities of Najaf and Karbala, all south of Baghdad.
With a referendum on Iraq's new constitution less than three weeks away, violence in the poor Shi'ite district could deepen opposition among Sadr's supporters who are bucking mainstream Shi'ite support for the constitution.
Shi'ite unity has been seen as critical for passage of the basic law, which most in the minority Sunni Muslim community oppose.
A statement read to reporters by an official with Sadr's office accused US forces of trying to draw them into a battle ''aimed at destroying Iraqi towns, particularly those in pro-Sadr areas and . . . to prevent al-Sadr followers from voting" in the referendum.
The two bicycle bombs hit marketplaces, the first in Hillah, about 60 miles south of Baghdad, where one person was killed and 48 wounded. The second bomb went off in Musayyib, about 40 miles south of Baghdad. It killed at least six and wounded 17, including the city police chief, according to police Captain Muthanna Khalid Ali.
Police also reported finding at least seven bodies in four separate locations in Baghdad -- six men who had been bound and shot, including one identified as a policeman, and a woman in her 20s who seemed to have been strangled and tortured.
Authorities said assailants kidnapped a Baghdad school principal on his way to work, and a mortar shell targeting an Iraqi Army checkpoint in western Baghdad wounded four Iraqi soldiers. In Samarra, 60 miles north of Baghdad, three mortar shells landed in a residential district. One shell hit a house, killing seven members of one family, including children, according to police Captain Laith Muhammed.
A US soldier also died yesterday and two others were injured when their vehicle rolled over while on patrol near the Jordanian border, the military reported. The death raised to 1,914 the number of US service members who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.
In Britain, Prime Minister Tony Blair gave no ground in the continuing dispute with Iraqi officials in the southern oil hub of Basra, saying yesterday that an arrest warrant against two British soldiers had no legal standing.
''We will do whatever is necessary to protect our troops in any situation," Blair told the BBC.
Basra authorities issued the warrants after the two soldiers, working undercover, were arrested Sept. 19. Rioting ensued when British armor surrounded the prison where the soldiers were detained, and that night the armored vehicles crashed through the prison wall and freed the men. British authorities said the soldiers were in the hands of militiamen loyal to Sadr, not the police.
In the meantime, the Basra governor has demanded that Britain apologize for the operation, in which five Iraqis reportedly died. Governor Mohammed al-Waili also said Britain must pay compensation for the casualties, and he ordered government officials to end cooperation with the British.
The Basra mayhem and subsequent bad blood between the British and residents in the predominantly Shi'ite region followed the arrest earlier this month of local Mahdi Army boss Sheik Ahmed Fartosi by British forces.
Shi'ite militiamen are believed to have infiltrated police forces in the south.