Sharks will be shot on sight if they threaten humans, under a new plan brought in for the start of Australia's summer.

Fisheries officers and water police have been given the authority to kill sharks longer than three metres - but only if they are endangering life and if they cannot be driven offshore.

The plan was introduced by the state of Western Australia, and confirmed by a spokesman for Fisheries Minister Kim Chance on Wednesday.

Last year, three people were killed in shark attacks off Australian beaches, including a bloody attack at Perth's popular Cottesloe beach.

In the attack last November, 49-year-old Ken Crew was killed, and his friend injured, while participating in an early morning swimming club.

Red tape cut

Fisheries officials followed the shark - a 4.5m Great White - for some time after the attack, but they did not have the authority to kill it. The only person with the authority to make such an order was the then Fisheries Minister, Monty House.

But he was in a meeting, and the shark escaped.

Great whites are protected in Australia, but officials are anxious to put public safety first. The new plan is aimed at making sure dangerous sharks are killed before any more beach-goers are hurt.

Deaths by shark attack are rare, but attacks are on the increase. However, there are also more swimmers and surfers, say experts.

Seals, sea lions and dolphins are among the normal diet of great white sharks, and experts say that surfers in wetsuits could be targets as they resemble seals.