Lifeguards closed down a portion of La Jolla beach Saturday after kayakers spotted a large hammerhead shark in the waters, showing signs of aggression, the Associated Press reported .

The sighting of the shark, which was about eight to 10 feet in length, prompted lifeguards to close a 1.5-mile stretch from La Jolla Cove to Scripps Pier Saturday afternoon.

The lifeguards made the decision to shut down the beach after analyzing video footage taken by a kayaker of the shark, which was last seen in the south end of La Jolla Shores near Avenida De Playa, according to ABC 7.

The shark was acting aggressively towards a group of kayakers and followed them all the way back to the beach, San Diego Fire-Rescue spokesman Lee Swanson said.

The size, species and aggressive conduct of the shark warranted the closure, according to a marine biologist at the Scripps Institution of Oceanography.

Lifeguards will assess the situation Sunday morning and decide whether or not the beach should be reopened to the public.