Asylum-seekers from Afghanistan being escorted to an Australian detention centre doused their boat in petrol before an explosion that killed three people and left two others missing at sea.
The government said the exact details of the blast on the rickety wooden boat hundreds of miles offshore were not yet known. "Everyone would like to know was this an accident or was it sabotage?" the Home Affairs Minister, Bob Debus, said.
Thirty-four people were airlifted to hospitals in Australia. A search was under way for two missing refugees. Four Australian navy personnel who were on board the vessel were among 48 people injured.
The asylum-seekers may have set the boat alight fearing that they were being escorted away from Australia. The navy intercepted the boat on Wednesday.