Search On For Missing People In Australia's Crocodile-Infested Waters

An asylum-seeker boat has reached Australia for the first time in almost four years, the government said Monday, with many of those on board the Vietnamese vessel fleeing into mangrove rainforest after it ran aground in crocodile-infested waters.

Locals said passengers from the rickety vessel disappeared into the dense forest near the Daintree River, north of popular tourist city Cairns, in the tropical far north of Queensland state on Sunday.

They will have to avoid crocodiles, venomous snakes and giant cassowaries - one of the world's deadliest and aggressive birds - that all call the ancient Daintree rainforest home.

Queensland Police Minister Mark Ryan told the Australian Broadcasting Corporation 15 passengers had been found so far.

The ABC added that two others, including the boat's captain, were still missing. The Brisbane Courier Mail reported that up to 20 were unaccounted for. It said those detained were well dressed and in good health.

State Emergency Service area controller Peter Rinaudo said earlier his crews were searching through the mangroves and near the mouth of the river, reportedly with dogs.

"It'll be a hard slog, it's still quite warm in there and it'll be tough conditions for the guys," he told the ABC.

"I hope the people, however many there are, get located - it's not a nice area for them to be in."

Home affairs minister Peter Dutton said the partially sunk vessel had come from Vietnam and was the first boat of asylum-seekers to reach the country since 2014.

"Australia, we believe, has received the first... people-smuggling venture in over 1,400 days," he told reporters.

"We will work with the agencies to make sure we can repatriate these people back to their country of origin, once we understand the facts of the matter."

Dutton did not confirm how many passengers were on board or their nationalities.

Illegal fishing

Under Canberra's tough immigration policy, asylum-seekers who try to reach Australia by boat are either turned back or sent to remote Pacific camps where conditions have been widely criticised. They are blocked from resettling in Australia.

The United Nations and human rights advocates say the policy violates the 1951 Refugee Convention of which Australia is a signatory.

Dutton reaffirmed the government's stance on Monday, saying the boat's arrival was "a reminder that people-smugglers have not gone out of business".

"We've had a very proud record, over the course of the last few years, and we aren't going to take a backward step. The people-smugglers... will not succeed in putting people on to boats to get to Australia."

Most asylum-seeker boats that have arrived in Australia in recent years embarked from Indonesia, though some originated in Sri Lanka.

Former Border Force chief Roman Quaedvlieg tweeted Monday that Vietnamese fishing boats "have been illegally fishing in fleets" off the far north Queensland coast in the past two years due to their own depleted fishing stocks.

"Possible the Daintree vessel & crew have used this activity as a staging point to make Oz landfall & avoid returning to VN (Vietnam)," he added.