HUNTINGTON BEACH, Calif. — A demonstration with more than 500 people Sunday at the base of the Huntington Beach Pier has been declared an unlawful assembly, according to a police official.

"Basically, demonstrators started arguing with each other,'' Huntington Beach police spokeswoman Angela Bennett said. "We had no fights yet. The demonstration started to block traffic on Pacific Coast Highway and so we've asked them to disperse."

The demonstration started about 11:30 a.m. and was declared an unlawful assembly at 1 p.m., Bennett said.

"We're asking people to disperse," she said. "We have to get our people in place and follow through on the order."

Business operators along Main Street were boarding up windows.

Among them was the Wet Dog Tavern, which had "Local minority owned business" scrawled on plywood placed in front of it, the Orange County Register reported.