(bbc) - Several miles of coast in California have been closed after a 66-year-old man died in a rare shark attack.
David Martin was bitten as he swam in the Pacific Ocean off Solana Beach, 14 miles north of San Diego.
The retired veterinarian was training with a triathlon team 150 yards (137m) offshore when he was attacked across both legs before the animal swam away.
He was carried ashore and taken to the Fletcher Cove Park lifeguard station, but was pronounced dead at the scene.
Officials cleared all beaches within a 17-mile radius of the attack.
Eyewitness: 'it was a big bite mark'
'Get out of the water'
Beaches will be closed within eight miles of where the attack took place for the weekend.
The mayor of Solana Beach, Joe Kelleejan, said: "We are very concerned about public safety, we are wanting to make sure everybody gets out of the water, not only on Solana Beach but in the surrounding area. The shark is still in the area, we are sure of that."
The shark was "probably" a Great White Shark, officials said.
Shark attacks are extremely rare: since records began in the 1950s, there have been only 11 fatal shark attacks off the California coast, according to the state's Department of Fish and Game.
Worldwide, there were 71 shark attacks recorded last year, of which only one was fatal.