BAGHDAD -- They wear police uniforms and drive official police vehicles, but the main priority of the rival militias that have usurped Basra's police force is not to maintain law and order.
Instead, they have turned Iraq's third-largest city into a patchwork of rival fiefdoms, where competing militias run corruption scams and kill their rivals, dumping the bodies into a garbage dump known as the Lot on the outskirts of the city.
Although British troops have earned plaudits for avoiding the sledgehammer tactics of American troops in Sunni Arab areas to the north, questions are being asked about the wisdom of Britain's "softly, softly" policy.
British officers, however, say they have little choice in the matter, insisting that troop strength has been insufficient to deal with the problem.
"Quite frankly, we have one brigade here and we've worked bloody miracles," said an officer in Basra who asked not to be identified. "We have had to let the Iraqis get on with it."
There was a sense of inevitability about the chaotic scenes in Basra on Monday, when British tanks smashed the walls of an Iraqi prison to free two undercover British soldiers seized earlier by Iraqi forces.
British officials had been keen to emphasize the relative tranquillity of the city in comparison with Baghdad and other towns to the north.
But behind the scenes is growing unease at Basra's descent into lawlessness and on the increasing influence of Iran on the city's main political factions.
Troops were ordered not to stop if challenged by police officers in case they were militiamen linked to attacks that, this month alone, have resulted in the deaths of three British soldiers and eight Americans in the Basra region.
The raid to rescue two Special Air Service commandos held by a militia that operated as part of Basra's police force has destroyed the pretense of a normal relationship with Basra's authorities.
The group holding the two soldiers blithely ignored instructions from the government in Baghdad to release them, leading many observers to ask who really controls the city.
In May, Basra's police chief, Hassan al-Sade, acknowledged that he had lost control of 75 percent of his 13,750-strong force, saying they either worked for political factions or were involved in attacks on coalition forces.
For his honesty, Basra's governor, Mohammed al-Waili -- who condemned the British raid to free the commandos as "barbaric, savage and irresponsible" -- fired him.
Since the United States handed over sovereignty to an Iraqi government in June 2004, Basra has become one of the country's most conservative Shi'ite bastions.
The city is essentially divided among three factions, although even they are riven by internal squabbles.
The Mahdi's Army of Sheik Muqtada al-Sadr, the cleric who twice last year led bloody confrontations against U.S. forces, is the smallest but is gaining ground in two of Basra's largest suburbs.
The Supreme Council for Islamic Revolution in Iraq (SCIRI), the largest party in the ruling coalition, is officially the largest faction and its Badr Brigade militia is accused of many of the assassinations.
SCIRI, however, often is outmaneuvered by the Fudala party, which fell out with Sheik al-Sadr but follows the radical strictures of his father, Mohammed Sadiq al-Sadr.
It is led by Mohammed Yaqubi, who has close ties to grand ayatollahs in the Iranian holy city of Qom. All three groups are determined to some extent to turn Iraq into an Islamic republic modeled on Iran.
"Iran has a very strong influence across Basra," said respected Iraqi member of parliament Ali al-Dabbagh. "It's not just the Sadrists. Individuals in each and every party are receiving financial backing from Iran."