HUNTINGTON BEACH, Calif. (AP) — Bicycle salesman Bert Etheredge locked down the shop where he works and sent customers and co-workers into a back room when he saw a raucous mob moving up the main street of a California beach town after a popular surf contest.

Moments later, the wild crowd yanked out a stop sign and rammed it through the window of the Easyrider shop before stealing a bike.

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“It was like a flood of people,” Etheredge said. “A running from the bulls kind of thing.”

More than 100 police officers responded to quell the disturbance on Sunday night in Huntington Beach, the city that bills itself as “Surf City USA,” after a fight broke out across from the beach where thousands of spectators had gathered for the popular nine day-U.S. Open of Surfing.

The raucous crowd toppled portable toilets, threw items from rooftops and smashed car windows along the popular downtown strip lined with restaurants, bars and surf and skate shops.

Police fired pepper balls and rubber projectiles to break up the melee.

One person was treated for injuries at a hospital after apparently being hit by a flying bottle and one of the rubber projectiles, Huntington Beach police Lt. Mitchell O’Brien said.

Seven people were booked into jail, one for investigation of assault with a deadly weapon after allegedly hitting an officer with a skateboard. Others were being investigated for drunken conduct and failure to disperse. Officers initially detained nine people, but two were later released.

“Any time you have thousands of people put together like this, you have the potential for things to go wrong,” O’Brien said.

Property damage could reach tens of thousands of dollars, he added.

Police were sifting through photos and video of the melee posted online and expect to make more arrests.

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At a news conference Monday afternoon, police Chief Ken Small defended the officers’ actions.

They “used a great deal of restraint when facing a barrage of bottles, bricks, rocks” and other objects, he said.

The U.S. Open of Surfing draws thousands of people every year to Huntington Beach. The event that ended Sunday included surfing, skateboarding and live music.

“We’re extremely disappointed and saddened by the disturbance,” said a statement on the U.S. Open of Surfing website. “We work tirelessly with city staff, police, fire and other agencies to ensure a safe environment for all.”

Shopkeepers say downtown — known for its scenic beaches and crashing surf — is often the scene of drunken bar brawls and rowdy behavior — but not rioting. Locals say some of the worst offenses come during the U.S. Open of Surfing when young partiers descend on the strip and leave a mess

“The people who come here aren’t here to shop. They’re just here to cause trouble,” said Michelle Hogan, manager of Island Cowgirl jewelry shop, which escaped the ruckus unscathed.  “There’s the drunkenness and the craziness but something like a riot is unheard of.”

Police said one of the arrestees was from Huntington Beach. The other six were from other Southern California cities.

On Monday, there was little sign of the disturbance except for a boarded-up window at Easyrider and a handful of television news trucks parked on the main strip. Beachgoers wearing flip-flops cruised by on colorful bicycles as tourists shopped for trinkets and stopped for lunch on a typically sunny summer day.

Tracey Boyle, 45, said she wasn’t fazed by the melee in the tourist town where she and her three children from Northern California had come to spend their vacation.

“It’s just something that got out of hand,” Boyle said. “You can’t imagine what it would be at a surf event — they seem too chill to get in that kind of confrontation, but they clearly did.”

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