LOS ANGELES -- Los Angeles Mayor Eric Garcetti has imposed a downtown curfew this evening,

Protesters were back in the streets Saturday. Garcetti said everyone must be off the downtown streets of the sprawling city by 8 p.m. local time until 5 a.m..

Several police cars were torched Saturday afternoon as some protesters ignored authorities' call for peaceful demonstrations following a night of violence that saw windows smashed, stores robbed and fires set. Los Angeles police arrested 533 people last night.