SYDNEY (AFP) - A teenager who escaped a shark attack that killed his friend in western Australia has described how he fired his spear gun into the suspected great white as the authorities searched for the animal on Tuesday.

The victim, named by local media as 17-year-old Jay Muscat, died after he was bitten on the leg by a shark while spear-fishing off Cheynes Beach, near Albany in the southern tip of Western Australia (WA) state, on Monday.

His friend Matt Pullella wrote on Facebook that "the shark hit me first then attacked Jay", The West Australian reported. "The shark turned and came for me, I pushed the speargun down its throat and fired the gun!" he wrote, adding that he estimated the animal to measure 4m to 5m long. "This is something no one should ever have to see."

WA's Department of Fisheries said Cheynes Beach would remained closed while equipment was deployed from boats to try and catch the shark, adding that it was most likely to be a great white.

"One of them (boats) will be setting (drum) lines, the other will be doing patrols in the nearby regions," Department of Fisheries spokesman Rick Fletcher told the Australian Broadcasting Corporation.

"One of the people involved in the attack actually shot at the shark with a spear gun, so the shark may be injured so we are going to have a look to see if we can find the shark if that is the case."

The attack was the second fatal mauling in Australia since Dec 15, when a teenager was attacked while swimming near Rudder Reef off Port Douglas, northeast Australia.

A young surfer lost parts of both arms in an attack by two great white sharks off the south coast of Western Australia in October, prompting officials to catch and kill two of the animals in the area.

The state government had earlier this year abandoned a controversial catch-and-kill policy - where sharks are caught on large hooks attached to floating drums placed off beaches - after objections from the state's environmental agency.

Conservationists had also criticised the policy and called on the authorities to instead use non-lethal methods to reduce risks, such as closing beaches and erecting warning signs.

Experts say attacks by sharks, which are common in Australian waters, are increasing as water sports become more popular.