A shark sighting prompted authorities to close part of the Huntington Beach coast on Monday afternoon.

The water at Sunset Beach between Warner Avenue and Anderson Street will be closed for several hours “out of an abundance of caution,” according to a tweet by city officials at 2:19 p.m.

A beachgoer flagged down a lifeguard around 12:30 p.m. and said they saw a shark in the water, said Jennifer Carey, a city spokesperson. The person’s description indicated the shark was possibly older than a juvenile.

Under Huntington Beach’s shark sighting policy, officials close the water for a mile in each direction of a sighting if the shark is exhibiting aggressive behavior, or if it’s above a certain size, Carey said.

Based on the person’s description of the shark being potentially larger than a juvenile, officials opted to close the water, she said.

Lifeguards are monitoring conditions, Carey said, adding that shark sighting-related closures typically last around four hours.

No one should get back in the water until officials lift the alert, she said.

Information on when the beach will reopen will be posted to safebeachday.com/sunset-beach.

Further information was not immediately available.