Avalon Beach 

A 15-year-old surfing boy was badly injured in a shark attack in the popular beach of Avalon, near Sidney, Australia.

It is the third attack in this city in a month. The teenager was in the water with his father when he was attacked.

"Half an hour later the father heard a scream and turned to see his son thrashing about in the water. Fortunately the shark swam away and the boy was helped to shore by his father," police said in a statement.

The teenager was airlifted to hospital for treatment for leg injuries. The bites got through to the bone but the surfer had no fractures.

After the attack, several beaches were closed while water police and lifeguards were searching for the shark.

There are a lot of shark species in this area but attacks on humans are still rare.

The Great White, for instance, is a protected shark specie in Australia.