Huntington Beach shark sighting prompts water closure

A nearly 2-mile stretch of ocean in Huntington Beach will be closed off for much of Friday after a shark was spotted on Thursday night, according to authorities.

In a post to Instagram, the Huntington Beach Fire Department and Marine Safety Division said the closure will last until at least 4:30 p.m. Visitors won't be able to reach the water anywhere between Beach Boulevard and 17th Street, which extends about one mile in each direction from the pier.

The closure comes after a about 10-foot long shark was spotted in the water on Thursday evening, authorities said. Aggressive behavior by the shark was observed, authorities said.

"Staff will evaluate the possibility of reopening the water at that time based on ongoing surveillance and assessment," the post reads. "We ask all beachgoers to obey posted signs and remain out of the water until the closure has been lifted."

The closure will affect a major surfing competition, the Vans Jacks Surfboards Pro. The competition has been placed on hold for 24 hours, organizers announced. The shark was spotted within the competition zone on Thursday, but it was after the day's event had concluded.

Organizers say they hope to resume competition at 7 a.m. Saturday.