More than two dozen great white sharks swimming off the coast of Southern California forced swimmers out of the water and closed down beaches.

An Orange County Sheriff's Department helicopter crew spotted the first school of some 15 sharks Wednesday afternoon near Capistrano Beach, the Orange County Register reported.

Later Wednesday, another warning went out, CNN reported, this time in Long Beach, about 50 miles north of Capistrano Beach, after another group of at least 10 great whites was spotted.

As shark advisories went up, beachgoers were warned about entering the water “at their own risk.”

The OC Register reported a woman was bitten at an Orange County beach last month.

ENSENADA, MEXICO - SEPTEMBER 15:  Great White Sharks seasonally gather off the coast of Guadalupe Island; divers dive inside cages off the boat Nautilus Explorer in order to safely swim with the sharks on September 15, 2016, 150 miles off the coast of Mexico.  (Photo by Dave J Hogan/Dave J Hogan/Getty Images)

Credit: Dave J Hogan

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Credit: Dave J Hogan