Huntington Beach authorities today closed access to the waters off Sunset Beach, between Warner Avenue and Anderson Street, following a shark sighting.

A beachgoer flagged a lifeguard between 12:30 p.m. and 1 p.m., saying a shark had been spotted, said Jennifer Carey, a spokeswoman for the city of Huntington Beach.

The shark was estimated to be between 8 and 12 feet, Carey said.

“Based on those sizes, it may not be a juvenile shark,” Carey said.

The city has a policy that if a shark shows aggressive behavior or is a certain size, then the waters are closed for at least four hours, Carey said.

Access to the water could be reopened between 5 p.m. to 6 p.m., Carey said.

Visitors to the beach should check for updates, Carey said.