A professional surfer was mauled by a shark off the Australian east coast on Wednesday evening, officials said.

Brett Connellan, 22, was flown by helicopter to Sydney's St. George Hospital in serious condition after he was attacked 120 kilometers to the south off a beach near Kiama, a police statement said.

He suffered injuries to a thigh and a hand in the attack off Bombo Beach at 7 pm and was helped 100 meters to shore by a fellow surfer, Joel Trist, police said.

Trist told reporters on Thursday he paddled as fast as he could toward his friend when he heard him scream. The shark had vanished before Trist covered the 50 meters.

"I said to him: 'What's it like?' and he said: 'It's not good.' And at that point I knew something was horribly wrong," Trist said.

Trist said he dragged his friend on to Trist's board and the pair caught a wave to shore.

Ambulance Service spokesman Terry Morrow said two beachgoers who were off-duty nurses saved Connellan's life by applying a tourniquet made from a surfboard leg rope to his upper thigh before paramedics reached the scene.

"He had lost a large proportion of his left thigh, and the quad muscle was torn away right down to the bone," Terry Morrow told the Illawarra Mercury newspaper.

"He could've bled to death before we arrived on scene. He was very lucky the members of the public were there and acted as they did," Morrow said.

Connellan did not see the shark. Experts are examining his wounds to determine its size and species.