SAN DIEGO » A shark has been spotted in the waters off a San Diego County beach for the second time in two days, prompting lifeguards to extend an advisory warning beachgoers of the shark sighting.

Authorities say a kayaker who was fishing off the La Jolla coast reported seeing a hammerhead shark Sunday afternoon. The kayaker said the shark followed him as he paddled toward the shore.

San Diego Fire-Rescue spokesman Lee Swanson says lifeguards also saw the shark swim toward a swimmer before turning toward deeper water.

Swanson says a 1 1/2-mile stretch of beach from La Jolla Cove to Scripps Pier will remain under a shark advisory that was issued Saturday after a hammerhead shark circled a group of kayakers.

The shark’s apparently aggressive behavior prompted lifeguards to close the beach.