The decision, made by an all-white jury, caused a political outcry, and provoked fury in the predominantly black neighbourhoods of south-central Los Angeles.

An angry crowd, chanting "Guilty! Guilty!", tried to storm police headquarters in the business district, before setting fire to shops and vehicles.

Motorists were dragged from their cars and beaten, cars were overturned and set alight, and at least five people were shot dead.

The violence is the worst in the city since the Watts riots of 1965, in which 34 people died. The Governor of California, Pete Wilson, has declared a state of emergency, and called in reinforcements from the California Highway Patrol.

'Murder and destruction'

In a brief televised statement, President Bush said the "murder and destruction" on the streets of the city must be stopped. He also spoke of his concern at excessive use of force by the police.

The case centred on a video, taped by an amateur cameraman in March last year, which caught the scene as the four police officers beat, kicked and clubbed unemployed labourer Rodney King for 81 seconds while other officers looked on.

The tape was on television networks across the world a day later, and became a focus for accusations of racist brutality against the LAPD.

Throughout the two-month televised trial, the four accused police officers - Laurence Powell, Stacey Koon, Timothy Wind and Theodore Briseno - argued that they acted in self-defence to restrain Mr King, who they said was aggressive and resisted arrest.

Following the verdict, Mr King's lawyer said his client was "speechless - in a state of shock and outrage". He plans to go ahead with his $56 million private suit against the city and police force.

State Senator Ed Davis, himself a former city police chief, said he was "shocked and flabbergasted" by the verdict. "Having seen the video, like millions of other people," he said, "I cannot accept this as police conduct for California."

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