CALIFORNIA (REUTERS) - Police in California on Sunday (Nov 21) were seeking about 80 suspects who they said swarmed into a Bay Area Nordstrom department store in a coordinated robbery, ransacking as much as they could carry and fleeing in cars they had parked outside.

Three people were arrested at the scene of the "organised theft" reported shortly before 9 pm local time on Saturday in suburban Walnut Creek, about25 km east of Oakland, police said.

"The remaining participants in this criminal mob fled from the area in cars at high speeds," Walnut Creek police said in a statement on Sunday.

The robbery followed another brazen mob-heist of high-end stores on Friday night in San Francisco's Union Square, about40 km to the west.

Video posted by a KNTV television reporter showed several people running out of the store with merchandise and climbing into about 25 parked cars that ringed the building and jammed traffic on the streets.

"It was crazy for a second," said Brett Barrette, a manager of a restaurant across the street, who told KPIX-TV that the thieves wore ski masks and were armed with crow bars and weapons.

"All the guests inside were getting concerned."

Police said the suspects assaulted two Nordstrom employees and pepper-sprayed another. They said they are reviewing surveillance footage in an effort to identify them.

Arrested at the scene were Dana Dawson, 30, and Joshua Underwood, 32, of San Francisco, and Rodney Robinson, 18, of Oakland, police said.

Charges brought in the arrests included robbery, burglary, conspiracy, possession of stolen property and illegal possession of a firearm by a felon, police said.