A surfer was gnashed by a shark on Monday in the third similar attack within a month off the north-eastern coast of Australia, police said.

The man, aged in his 30s, was attacked at Byron Bay, 36 kilometers (22 miles) north of Ballina, where a 25-year-old man sustained minor leg injuries while surfing with friends on Oct. 12, a police statement said. He was driven to the local Byron Bay hospital by a friend.

A witness, Geoffrey Knapp, told local ABC radio that the victim had been lying on his board when the shark attacked and tried to flip him over, with the fibreglass surfboard bearing the brunt of the attack.

He said the surfer had endured "only a superficial wound."

The attack took place at Broken Head beach near Byron Bay, 20 kilometres north of Ballina, where another 25-year-old man was injured in an attack two weeks ago.

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 kilometers (350 miles) north of Sydney.

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

After Monday's attack all the beaches across Byron Bay were closed for 24 hours, police said.

The latest attack comes just one day after anti-shark net protesters campaigned in Ballina to demonstrate against government plans to place anti-shark nets along areas of the coast.

The NSW government had reversed its policy not to use the nets after the 15-year-old surfer was bitten earlier this month. It was on top of a plan to install "smart" drumlines along the beach.

The shark nets, which are suspended from floats parallel to the coastline, can entangle and kill other marine wildlife, including endangered species like turtles and dolphins.

Monday's attack is the 13th in the past eighteen months on the north-eastern coast of NSW, including a fatal incident in February 2015 in which Japanese surfer Tadashi Nakahara died