Governor Pete Wilson mobilized the National Guard tonight as angry rioters rampaged through the streets of the city, smashing and looting stores, beating passing motorists and setting scores of fires.

The violence was ignited by the acquittals of four Los Angeles Police officers who were shown on videotape beating and kicking a black motorist, Rodney G. King, in what has become a symbol here of the antagonisms between the city's minorities and its peacekeepers.

Throughout the night it intensified in the inner city and flared downtown as looters roamed near City Hall and in a shopping area in the mostly white Westwood neighborhood in the worst violence since the 1965 Watts riots.

Buildings were set afire and looted, a freeway was closed, cars were stopped and their drivers beaten, government buildings were vandalized, and the air was filled with the smell of smoke and the sound of police sirens.

Mobs of young men rampaged through the streets overturning and burning vehicles, smashing windows and spraying graffiti. Police officers, firefighters and news helicopters reported being shot at.

The Governor announced the mobilization six hours after the verdict and after the failure of a passionate plea for calm by the city's Mayor, Tom Bradley, who is black. Mr. Bradley later said a curfew would be imposed Friday night.