A woman struggled in vain to drag her friend from a crocodile's jaws during a late night swim off an Australian beach.
The pair were in shallow water at Thornton Beach in the World Heritage-listed Daintree National Park in Queensland state when the 46-year-old woman was taken by the crocodile at 10:30pm local time on Sunday.
Police Senior Constable Russell Parker said: "Her 47-year-old friend tried to grab her and drag her to safety but she just wasn't able to do that."
He said the two women were not locals and might not have been aware that the area was well known as a crocodile habitat.
A rescue helicopter fitted with thermal imaging equipment failed to find any trace of the missing woman on Sunday night.
The search resumed on Monday with a helicopter, boat and land-based teams.
The missing woman is from Lithgow in New South Wales state.
The survivor, from Cairns, 58 miles south of Thornton Beach, was taken to a hospital in Mossman suffering from shock and a graze to her arm inflicted as the crocodile brushed against her, Queensland Ambulance Service spokesman Neil Noble said.
"The report that we have from the surviving woman is that they felt a nudge and her partner started to scream and then was dragged into the water," he said.
The two women were not locals and might not have been aware that the area was well known as crocodile habitat, police said.
But Warren Enstch, who represents the area in the Australian Parliament, said the beach was beside a creek where tourism operators run crocodile-spotting tours.
He said the two tourists had to have seen plentiful crocodile warning signs in the region.
"You can't legislate against human stupidity," Mr Entsch said. "If you go in swimming at 10 o'clock at night, you're going to get consumed."
The attack occurred near where a five-year-old boy was taken and killed by a 14ft crocodile from a swamp in 2009 and a 43-year-old woman was killed by a 16ft croc while swimming in a creek in 1985.
Darwin-based crocodile expert Grahame Webb said while most crocodiles were found in rivers, swamps and other protected waterways, open beaches in northern Australia were not safe.
"There've been quite a lot of attacks off beaches and off coral reefs where people are snorkelling," he said.
Crocodile numbers have boomed across Australia's northern tropics since they became a protected species in 1971, and they pose an increasing threat to humans.