Australian authorities were on high alert for the arrival of further refugee boats as a political row unfolded over a fatal blast on board an illegal smuggling vessel.
The explosion off Australia's northwest coast on Thursday killed three people and injured dozens but the death toll is expected to rise, with two people still missing and five on life support, authorities said.
A political furore deepened over refugee policies, with widespread reports that a second boat carrying up to 100 people had been detected off Australia's north coast and would arrive in its waters within days.
Thirteen refugee boats, six of them this year, have been intercepted in Australian waters or made landfall since the centre-left Labour government rolled back tough measures against asylum seekers in September.
Kevin Rudd's Labour government, which came to power in late 2007, scrapped a widely criticised system under which asylum seekers, including children, were regularly held in detention centres for years.
Asylum seekers arriving by boat are now held on Australia's Christmas Island and their claims must be expedited, with cases reviewed every six months by an ombudsman.
The conservative opposition party has blamed the softer policy for an influx of illegal entries, and said police warned the government weeks ago that changes to its border-protection system had made Australia an attractive target.
Of the two crew and 47 refugees, believed to be mostly men from Afghanistan en route from Indonesia, 41 were injured, with several rushed into surgery after a rescue operation involving medics, the navy and police.
Several blast victims remained on life support while at least a dozen others were critically injured, with severe burns to most of their body, doctors said.
