A surfer has been killed by a shark off a southern California beach as his friend watched in horror.
Francisco Solorio, 39, died in the attack off the coast of Surf Beach in Lompoc, the Santa Barbara County Sheriff's Department said. He was bitten in his upper body.
The attack at Surf Beach in Lompoc, off Vandenberg Air Force Base, was reported by another surfer at about 11am on Tuesday.
Mr Solorio "had a friend who he was surfing with who saw the shark bite or hit the man", said Sgt Mark Williams. "His friend ended up swimming over and pulling him from the water where he received first aid."
The friend started first aid while another surfer called for help, but the victim was pronounced dead by paramedics at the scene.
The US Air Force said Mr Solorio was not affiliated with the base, which allows public access to some of its beaches. The type of shark involved and other details were being investigated.
It was the latest shark attack fatality at Surf Beach, about 150 miles north west of Los Angeles. In October 2010 Lucas Ransom, a 19-year-old student at the University of California, Santa Barbara, died when a shark nearly severed his leg as he body-boarded.
Hundreds of miles south near the coast of San Diego, a 15ft great white shark is believed to have killed triathlete David Martin in 2008. And last month, warning signs were posted at Santa Barbara Harbour, about 65 miles south east of Surf Beach, after a 14ft great white shark was spotted by a surfer. Similar shark sightings occurred along California's Central Coast throughout the summer and warnings were issued.
All beaches on the base's coastline would be closed for at least 72 hours as a precaution, Colonel Nina Armagno later said.
Death by shark attack is rare. There is an average of 65 shark attacks around the world every year, which typically result in two or three deaths, according to the Pew Environment Group.