Woman suffers critical injuries after shark attack at Sydney's Coogee beach

A woman is in a critical condition after being bitten by a shark at a beach in Sydney's east.

Emergency crews were called to Coogee just before 11am on Saturday after reports of a "large" shark attack, described by Randwick City Council as 3 to 4 metres in length.

Medical teams, paramedics, the Toll rescue helicopter and police officers on arrival found a 35-year-old woman being assisted by off-duty doctors and off-duty lifeguards "applying tourniquets to her limbs".

Mike Corlis from NSW Ambulance said the woman had been reportedly swimming about 30 metres offshore when the attack occurred.

"She has quite massive wounds to her left lower leg and her arms," he said.

"And she's been given blood products whilst here. She's been transported by road to St Vincent's Hospital in a serious to critical condition.

"She was brought to shore by an off-duty lifeguard and lifesavers on the longboard."

He added that her wounds would require a lot of surgery.

In a statement, the council said she had been swimming between the flags.

Mayor of Randwick City Council Dylan Parker said there were a number of people who witnessed the "shocking incident".

"It occurred literally metres from the sand, so there have been lots of quite shaken individuals who have spoken to me, including those who actually responded and witnessed the incident," he said.

"A huge and heartfelt thank you to all of those who did respond, including community members who lent assistance.

"Hopefully the lady who is in a pretty bad condition right now pulls through but our heart goes out to her."

'We heard a really chilling scream'

ABC journalist Patrick Stack was at the beach playing with his child in the water on a "beautiful winter's day" when the attack took place.

He described what played out as "extremely concerning".

"Lots of people [were] swimming in the water when we heard a really chilling scream going out across the beach," Mr Stack said.

"And at first you wonder whether it's sort of kids mucking around or something like that.

"But the quick follow of the shark alarm sort of made it clear that it was something much more serious and much more sinister."

He said he was about 50 metres away from where the woman was pulled from the water by a man on a surf rescue boat with  help from a paddle board rider.

The community, according to Mr Stack, is very tight-knit and the majority of people at the beach were familiar faces.

He said they have been left in "stunned silence".

"In winter, it's not peak sort of tourist season, so it's very familiar faces all down here to do their weekend swim and hearing local swimmers floating around nearby saying that they saw a shark swim underneath them.

"Obviously eerie sort of scenes and lots of distress amongst the community and not what you sort of expect when you come for your Saturday swim at the beach."

'Last thing you'd expect'

Shawn Buttling lives a block away from the seafront.

He told the ABC News how he rushed to the beach after hearing multiple police cars, ambulances and sirens racing past his home.

"When I got down there, there was already a surf lifesaving rescue underway and an elderly couple nearby told me there had been an immense amount of blood," he said.

"I'd done my morning walk around seven o'clock. The water was clear, people were swimming and there were groups training in the ocean. It was the last thing you'd expect.

"My initial reaction was just unbelievable."

Jet skis were deployed offshore while emergency crews treated the victim on the sand.

"When I initially got here there were two jet skis out instantly while they were still attending to the person on the beach. That's when we realised they're just trying to find the shark."

He said authorities established exclusion zones around the beach as large crowds gathered.

"The scene is still crowded down here. All the crowds are on the sidewalk, they're not down on the beach, just looking at the helicopters."

Coogee Beach along with others in the Randwick Council area have been closed for 24 hours.

"Lifeguards are currently in the water, patrolling up and down looking to identify the shark. And we will reopen when it is safe to do so," Cr Parker said.

"We will not reopen our beaches until we're advised that it's safe to do so."