Authorities have ordered a shark be destroyed after it killed a man in an attack close to shore at a popular Perth beach.

It was the second shark attack in Western Australia in days, with emergency services called to Sorrento Beach about 10.30am on Friday after reports of a swimmer in distress.

Emergency services remain on the scene this afternoon. 9News

9News understands two men were swimming about 15 metres from shore when one of them, aged in his 60s, was taken by a shark.

A great white shark about five metres long was spotted by aerial surveillance in the area, but it is unclear if it is the animal responsible for the attack.

The man’s friend witnessed the tragedy, as did dozens of onlookers on the beach.

“I was sitting here looking out the ocean and saw a splash, and then a guy came and saw me and said, ‘Shark, shark’,” Darrel, a witness, said.

A shark spotted off Sorrento Beach after an attack. 9News

Authorities have ordered a shark be destroyed after it killed a man in an attack close to shore at a popular Perth beach.

The man’s friend witnessed the tragedy, as did dozens of onlookers on the beach. 9News

“I feel for his mate, he’s apologising, he said, ‘I couldn’t save my mate’. I said, ‘You couldn’t have done anything.’

“I don’t really know how to put it into words, it’s just a shocking thing.”

Ingrid Mitchell swims at the beach every day and said the attack took her by surprise.

“There was other swimmers in there, there were swimmers down there, just near the seaweed, and there was one poor girl there who was sunbaking, and she saw the whole lot as well,” she told 9News.

“You sort of think sharks, dawn and dusk [and] when it’s a bit overcast [is when they attack], but look at the day, it’s amazing.”

Police received reports of a swimmer in distress after 10am on Friday. Hannah Murphy

Mike Munro had been cycling along the beach at the time.

“I don’t really know how to put it into words. It’s a shocking thing,” he said.

St John Ambulance sent three vehicles to the scene under priority one conditions about 10.15am, but they were stood down.

Water Police and a Police Air Wing were deployed, while vessels from the Department of Primary Industries and Regional Development (DPIRD) were also part of the search and recover operation.

Fisheries Minister Jackie Jarvis has issued an order to have the shark destroyed.

Authorities had been tracking it since the morning, but will have to catch it before it can be killed.

9News Perth reports that whilst efforts to catch the shark had been unsuccessful, authorities planned to work throughout the weekend.

Authorities have ordered a shark be destroyed after it killed a man in an attack close to shore at a popular Perth beach.

Authorities had been tracking it since the morning, but will have to catch it before it can be killed. 9News

Authorities have ordered a shark be destroyed after it killed a man in an attack close to shore at a popular Perth beach.

Sorrento Beach has been closed, and the City of Joondalup council has closed all beaches. 9News

Sorrento Beach has been closed, and the City of Joondalup council has closed all beaches from J210 Marmion BEN sign to J37 Iluka BEN sign until at least midday on Saturday.

A shark expert has been drafted in by police to investigate how and why the attack may have occurred.

The latest shark attack is the second to occur in Western Australia this week.

Mel Ismail (left) and the damage done to his board in the shark attack. 9News

On Monday, 56-year-old surfer Mel Ismail was attacked by a shark off the waters of Glenfield Beach in Geraldton.

He was saved by another surfer, Shannan Dunn, and suffered serious leg injuries.