Beaches from Bondi to Maroubra have since been closed.

A woman is fighting for life after being bitten by a shark believed to be between 3m and 4m long at Sydney’s iconic Coogee Beach.

The woman, believed to be in her 30s, was swimming with two friends within the flagged area when she was attacked on Saturday morning.

Bystanders pulled her from the water before emergency services arrived about 11.15am.

She suffered serious injuries to her arm and leg, police said.

The woman was later rushed to St Vincent’s Hospital by ambulance about 11.50am.

Randwick City Council said she was “breathing but in a critical condition”.

Locals told 7NEWS.com.au the woman was one of three swimmers about 20m offshore near the centre of the beach when she was attacked.

They said it appeared she had suffered bites to her thigh and upper arm.

A witness told 7NEWS there was a large amount of blood in the water following the attack.

“It’s just everyone sitting on the stairs and enjoying this beautiful day and then her screams, which didn’t sound right,” the witness said.

“And then just one girl sort of coming to shore and then this shark alarm and a lot of blood in the water.

“It just took a moment to kind of realise that this was actually a shark attack.”

Joanne Feddler, who was swimming nearby at the time, told 7NEWS she started heading back to shore after hearing “the most terrifying screams”.

“When I got out of the water, I could see that there was this big dark patch in the water,” Feddler said.

“I got onto the beach and it was really quick — the rescuers came and they pulled her out of the water.

“I saw when they pulled her out of the water, she had a massive chunk of her leg bitten off.”

Having swum in the area for eight years, Feddler said she never imagined a shark attack could happen at Coogee.

“She was literally 50m behind me. I had literally been swimming in the same water. It was just the most shocking thing.”

Another witness also said it was shocking to see a shark attack at Coogee.

“Five years, I’ve never, ever seen a shark attack here before, so it’s shocking for the community, yeah,” she said.

Coogee is widely regarded as one of Sydney’s calmer, family-friendly beaches.

Crowds broke into applause for a man who pulled the woman from the water following the attack.

“You’re a hero,” one onlooker yelled as he was swamped by others and lifeguards who patted him on the back while walking up the beach.

Randwick City Council said the shark involved is believed to have been between 3m and 4m long.

Beaches from Bondi to Maroubra have since been closed.

“Unsurprisingly, there are lots of very shaken up individuals right now having witnessed a very scary incident,” Randwick Mayor Dylan Parker said.

“Our beaches are closed for at least the next 24 hours and we strongly advise the community to stay out of the water.

“Our hearts and thoughts go out to the woman, her friends and family. The whole community is behind her and wishing her a speedy recovery.”

The NSW Government’s SharkSmart app showed a tagged tiger shark measuring 2.63m was released off North Bondi at 10.22am on Saturday, just over an hour before the attack at Coogee.

Authorities have not linked the shark to the incident, and it is not known what species was involved.

The latest attack has prompted renewed calls for greater investment in shark mitigation measures.

Central Coast councillor Jared Wright said the incident highlighted the need for more shark surveillance programs and shark listening stations at beaches across NSW.

“There has been a clear rise in the number of shark attacks over the past 12 months, which highlights that there is still more to be done to help keep beachgoers safe right across NSW,” Wright said.

He said Coogee Beach did not currently have an active Surf Life Saving NSW drone patrol or shark listening station and argued those measures should be expanded to more beaches.

SOURCE: https://7news.com.au/news/woman-injured-in-suspected-shark-attack-at-sydneys-coogee-beach-c-22425856