British raid Iraqi jail

This makes absolutely no sense to me:

British armored vehicles backed by helicopter gunships burst through the walls of an Iraqi jail Monday in the southern city of Basra to free two British commandos detained earlier in the day by Iraqi police, witnesses and Iraqi officials said. The incident climaxed a confrontation between the two nominal allies that had sparked hours of gun battles and rioting in Basra's streets.

An Iraqi official said a half-dozen armored vehicles had smashed into the jail, the Reuters news agency reported. The provincial governor, Mohammed Walli, told news agencies that the British assault was "barbaric, savage and irresponsible."

British officials said three soldiers were hurt in the day's violence, in which at least one armored personnel carrier was destroyed by firebombs. Iraqi officials said at least two civilians were killed.

In London, authorities said the two commandos were released after negotiations. But the BBC quoted British defense officials as saying a wall was demolished when British forces went to "collect" the men.

Can anyone explain this to me? Didn't the British help liberate Iraq? Or am I missing something?

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Update (9/21/05): Check out Juan Cole's must-read post at Informed Comment: "The British seem to be facing increasing risks of danger from Shiite militias in Basra. In particular, the Mahdi Army of Muqtada al-Sadr, a small group in Basra though more popular in East Baghdad, is suspected of setting roadside bombs to hit British patrols. The British attack on the jail, however, may well have played into Sadr's hands, making him a heroic figure to nationalist Shiites in Basra who previously had taken little interest in his puritanical movement."