Five civilians were killed and more than a dozen others reportedly injured in crossfire after a gunbattle erupted between British soldiers and insurgents who set a fire in a vegetable market Sunday, Iraqi police said.

Police Capt. Hussein Karim said insurgents started the fire in the market in south Amarah, 180 miles southeast of Baghdad, to lure soldiers to fight.

The British Ministry of Defense, however, said soldiers were sent to search the area because it was the site where a rocket was believed to have been fired. Upon arrival, coalition forces were attacked by small arms fire, the ministry said in a statement.

One British soldier was injured, and there were "a small number of terrorist casualties", but full details of the incident remained unclear, the ministry said.

The ministry could not confirm civilians were among those wounded and killed.

Elsewhere in Iraq, where 30 people died Sunday, a roadside bomb struck an Iraqi police patrol near a mosque in north Baghdad, killing one and wounding three others. Drive-by gunmen nearby also fired on a civilian car in a separate incident, killing the driver, police said.

Police in Baghdad also said they found two bodies, a Health Ministry security guard who appeared to have been shot in the head after being tortured and a taxi driver who was reported kidnapped yesterday in Dora, a southern Baghdad neighborhood.

Unidentified gunmen in Mosul also shot and killed a former Iraqi Army officer, police said. The assailants were in a speeding car and killed Ali Ahmed Abdullah with a machine-gun as he was walking in one of the city's commercial centers.

A roadside bomb in western Mosul killed one bystander and injured six others, police Col. Abdul-Karim Ahmed said.

The violence Sunday comes amid a stalemate in Iraq's government just one day after insurgents signaled the fight was still on after Abu Musab al-Zarqawi's death, posting an Internet video showing the beheading of three alleged Shiite death squad members.

After an already monthlong delay, the Iraqi parliament postponed its session Sunday to allow the main political blocs more time to agree on the exact powers of the Sunni Arab parliament speaker.

Prime Minister Nouri al-Maliki met with party representatives Saturday, but failed to break the deadlock.

The video — as grisly as any Al Qaeda in Iraq leader issued — was clearly designed to quash hopes that the Sunni-dominated insurgency might change tactics by ending attacks on Shiite civilians and institutions, especially the police.

Fellow Sunni insurgent groups sent condolences for Zarqawi in Internet messages Saturday and warned Sunnis not to cooperate with the Iraqi government, an apparent call for unity three days after U.S. forces killed the terror leader in a targeted airstrike.

"Iraq is the front defense line for Islam and Muslims, so don't fail to follow the path of the mujahedeen [holy warriors], the caravan of martyrs and the faithful," said Abdullah bin Rashid al-Baghdadi, the Shura Council's head.

The Jordanian-born Zarqawi was the defining face of Iraq's insurgency. His tirades against the nation's majority Shiites and calls on the once-dominant minority Sunni Arabs to rise up and kill them were matched by the killing of thousands of Shiites in attacks.

The video was the first known footage of beheadings to be posted by any insurgent group in months, and possibly timed to make clear to the U.S. and Iraqi governments that there will be no change in tactics even though Zarqawi is gone.

With its gruesome killings and militants chanting "Allahu Akbar", or "God is Great," the 15-minute video illustrates the depth of Shiite-Sunni rivalries.

Iraqi and U.S. leaders acknowledged that Zarqawi's killing was not likely to stop the insurgency, now in its fourth year. But they hoped it would rob his supporters of an iconic figure around which they rallied.

Also in Baghdad on Sunday, a roadside bomb struck an Iraqi police patrol car in the southern neighborhood of Dora, killing one officer and wounding eight others. Police in the neighborhood also found four unidentified bodies, all of which had been tortured and shot.

In other violence Sunday:

— A parked car bomb hit the busy shopping district of Karradah in Baghdad, killing at least four people and wounding 16,Lt. Col. Abbas Mohammed said. The blast shattered the facades of nearby shops and was the second strike in two days against the neighborhood, which is near a Shiite mosque.

— Gunmen in Baghdad's western Khadra neighborhood entered a popular restaurant and killed the owner. In a separate incident in the same neighborhood, two Shiite brothers were killed in a drive-by shooting.

— A medic in Baqouba was killed in a drive-by shooting while he waited in a bus station.