We have officers ... armed with a high-powered rifles and a shotgun, and they will destroy the animal

Police Inspector Alf Fordham

At Perth's popular Cottesloe Beach, where the attack took place in waist-high waters, a memorial service was held for Ken Crew, the 49-year-old father of three who was killed.

Mr House said although the shark belonged to a protected species, it could not be allowed to threaten more swimmers. "The community's safety is paramount," he said.

The shark also left another man with injuries to his legs and feet.

A 60-km (37-mile) stretch of beaches has since been closed.

Some 11 people have died from shark attacks in Australia between 1980 and 1990, but three attacks have occurred in the last two months alone.

Declining fish stocks

Declining fish stocks and more swimmers and surfers are the reasons being given by experts for the increased number of attacks.

Seals, sea lions and dolphins are among the normal diet of great white sharks.

Experts say that surfers in wetsuits could be targets as they resemble seals.

There have been more shark attacks in the 1990s than in previous decades, with 536 attacks, compared to 250 attacks in the 1980s and 200 in the 1970s.

The University of Florida's International Shark Attack File, which compiles the data, says the rising level of attacks is directly related to the length of time spent in the sea, adding people now spend more time in the water.

Search mounted

Police Inspector Alf Fordham said water police were armed with rifles and shotguns to kill the shark.

Divers will soon be able to deter sharks electronically

Police are using baited hooks to lure the shark to the surface, he said.

Hundreds of people were on the beach during the attack - believed to be the first fatal one in 30 years.

Many watched in horror from a nearby caf�, as the shark, estimated to be nearly 5m (16 feet) long, pursued Mr Crew and then ripped through his torso and severed his leg, just as he was metres from the beach.

"There was this massive fin," cafe owner Kim Gamble said. "There was a whole sea of blood and it was pulling the person."

Great White sharks normally attack their prey by taking a bite first and them letting them bleed to death.

Mr Crew died on the beach after losing part of his leg.

In September two surfers were killed near Elliston, South Australia.