A surfer is in critical condition after a shark attacked him in southern Australia.

Police said in a statement that the 26-year-old man suffered "serious leg injuries" when he was attacked Saturday about 40 kilometers (25 miles) south of Port Lincoln in South Australia state.

He was flown by helicopter in critical condition from a Port Lincoln hospital to the main hospital in the state capital, Adelaide.

Adelaide's The Advertiser newspaper reported a witness's description of a 6-meter (20-foot) great white shark biting off the surfer's leg, which had an ankle strap attached to his surfboard.

Sharks are common off Australia's beaches, but fatal attacks are rare. The country has averaged fewer than two deadly attacks per year in recent decades.