SYDNEY, Australia -- A shark bit a terrified surfer's board on Friday near the Australian coastal town where another surfer was mauled a day earlier, police said.

The 52-year-old surfer was not injured when the shark bit his board, leaving teeth marks in the fiberglass, while surfing off Lennox Head, 600 kilometres (350 miles) north of Sydney, a police statement said.

The surfer, who has not been named, was sitting on the board when the shark knocked him off, said Garry Meredith, a life guard at Lennox Head.

"The shark came back and had another crack, but it's just bitten the back of the board," Meredith said. "If he'd been lying on the board, it definitely would have got his legs."

A 32-year-old surfer Matt Lee remained in a critical condition at Gold Coast University Hospital on Friday after a shark seriously injured both his legs off Lighthouse Beach, 10 kilometres (6 miles) south of Lennox Head at the tourist town of Ballina. Beaches around the town were closed Thursday and again on Friday after the latest attack.

The surfers' contacts with sharks are particularly unusual given relatively few beach-goers are in the water during the current southern winter.

A junior surfing competition involving 270 children was underway Friday at Lennox Head when news of the second attack reached police, who called off the event.

Ballina was the scene of a fatal shark attack in February. Japanese tourist Tadashi Nakahara, 41, was surfing just north of Lighthouse Beach at Shelly Beach when police said a great white shark 3 to 4 metres (10 to 13 feet) long tore off both his legs.

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.