SYDNEY, Australia -- A surfer sustained teeth wounds to his thigh on Monday in the third shark attack off New South Wales state north of Sydney in a month, police said.

The man, aged in his 30s, was attacked at Byron Bay, 36 kilometres north of Ballina, where a 25-year-old man sustained minor leg injuries while surfing with friends on Oct. 12, a police statement said.

On Sept. 26, a 17-year-old surfer required stiches to close a leg wound after he was bitten by a shark off Ballina, 600 kilometres north of Sydney.

A 41-year-old Japanese surfer was killed by a shark off Ballina last year.

After the latest attack, a friend drove the victim to the Byron Bay hospital. The puncture wounds to his upper-left thigh were not life-threatening, police said.

A surfer who administered first aid at the scene, Geoffrey Knapp, said the victim had been lying on his board when the shark attacked. The fiberglass board took the brunt of the bite, Knapp said.

The victim "clearly saw the tail and he got the impression that the shark was trying to knock him off his surfboard and roll him over," Knapp told Australian Broadcasting Corp.

Hundreds of protesters gathered at Ballina on Sunday to demonstrate against government plans to place anti-shark nets along beaches around Ballina.

The nets, which are suspended from floats and run parallel to the coast, are not complete barriers to sharks and kill a wide variety of marine life. Environmentalists oppose them.

Police said beaches around Byron Bay would remain closed for 24 hours after the attack.