Swimmers and surfers were ordered out of the of the water and beach goers warned not to enter it Sunday after 25 sharks, many of them great whites, were spotted close to shore.
The sharks measured 8 to 10 feet and some were swimming within 25 yards of the beach, prompting the closure, officials said.
"If there's one in the eight-(foot) plus range, we usually close beaches for at least four hours, but this closure we're going to keep it for the remainder of the day," Nick Giugni, with the San Clemente City Lifeguard Department, told the Orange County Register. "We can't confirm it's going to be reopened, but we will reevaluate and make the safest call."
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The beach was closed for four hours after a shark was spotted around 10:30 a.m. There was another sighting near the San Clemente Pier around 1 p.m. The water was opened briefly around 3 p.m. However, an Orange County Sheriff’s Department helicopter caught sight of 25 sharks around 4 p.m., closing the beach for the day.
They planned to reevaluate the closure Monday morning.
The beach has only been closed two other times this year, according to the Los Angeles Times.
A shark bit a woman on her thigh in April who was swimming near San Onofre State Beach. A group of swimmers and paddler boarders were warned about a group of great white sharks next to them earlier this month, prompting a closure.
Area beaches have been under a shark advisory for about two weeks, according to the Register.
Although sightings are up, bites are rare.
"The chances of being bitten or attacked are like winning the Powerball," Giugni told the Times. "But, obviously, people win the Powerball."