Witnesses have described the “gruesome” shark attack off Sorrento Beach in Perth on Friday that left a swimmer dead.

The man was in his 60s, and a regular swimmer and member of the local surf club, according to 9News Perth.

Darrel Haythornthwaite told 7News the man’s friend had made it back to shore but was distraught. “He felt bad because he didn’t go back to save his mate,” he said.

Another witness, Ingrid Michell, said, “The shark took his friend from literally 15m off the shore.”

Michell said she was reluctant to get back in the water. “I’m a nurse, so I mean, I obviously see a lot of gruesome stuff, but to see somebody being mauled to death in the water in front of you is pretty hard to cop.”

It is understood WA’s Fisheries Minister Jackie Jarvis has issued an order for the shark, which witnesses described as six metres long, to be destroyed.

Emergency services attended Sorrento Beach about 10.30am on Friday after reports a male had been bitten by a shark while swimming along the coast.

Dozens of witnesses were on the beach during the incident. One told the ABC she was alerted to the attack when she was walking along the beach and saw a pool of blood in the water.

Emergency authorities confirmed the death after searching from the air and on the water. Photo: AAP

Authorities searched for the swimmer from the air and sea, but he died from the attack, with his remains found in the water, WA Police said.

The Department of Primary Industries and Regional Development is investigating the incident, the second shark attack off WA’s coast in five days.

The City of Joondalup has closed all beaches in the area, from Burns Beach in the north to Marmion in the south, until midday on Saturday as a precaution.

The fatality follows a shark attack on a surfer at a remote WA beach on Monday.

Sorrento Beach, in Perth’s north, is a popular swimming spot known for its calm waters. Photo: AAP

The man was seriously injured at Glenfield Beach, north of Geraldton in the state’s Mid West

He was taken to the nearby Geraldton Health Campus and is now in a stable condition.

Surf Lifesaving WA’s helicopter shark patrols began for summer last week.

They will operate initially on weekends before increasing to a daily frequency between Mandurah and Yanchep, and Rottnest Island to the west, from September 26 until the end of April.

Patrol flights in WA’s southwest between Bunbury and Hamelin Bay will run daily during school holidays and peak summer periods, and on weekends and public holidays at other times.

-with AAP