An injured woman has been pulled from a beach following a shark attack in Sydney’s south.

Emergency services were called on Gunyah Beach, near Bundeena, about 1.30pm on Friday following reports a shark attack.

NSW Police said a woman, believed to be aged in her 30s, was being treated by paramedics at the scene for serious leg injuries.

Witness Kevin McKay said people ran into the water to help the woman after being alerted by her screams.

“A woman with deep lacerations above the right knee. People were quick to jump in the water to bring her to shore and to apply pressure to stop the bleeding,” he told The Daily Mail.

“Local paramedics arrived within 19 minutes. I think she will be OK.”

A NSW Ambulance spokesman said the woman had been flown to Sydney’s St George Hospital in a serious condition.

Bundeena is a small village surrounded by national park and fronting the Port Hacking River.

Gunyah Beach is a quieter location than some in Sydney’s Sutherland Shire, and is often favoured by locals. It is known as a good spot for snorkelling.

-with AAP