Australia did all it could: Commander The acting head of Australia's border protection operation has praised the nation's professional and timely response to the fatal sinking of an asylum-seeker boat off Indonesia that's claimed up to 36 lives. As Prime Minister Tony Abbott was in Indonesia for talks with President Susilo Bambang Yudhoyono, his government was facing questions about its handling of the sinking off Java on Friday. But Operation Sovereign Borders Acting Commander, Air Marshal Mark Binskin, says Australian authorities took "every step available to them" in responding to the tragedy. Air Marshal Binskin denied reports of a 26-hour delay in responding to the unfolding crisis, after some survivors said they contacted Australian authorities on Thursday. He said Australian authorities first learned the vessel was in distress at 7.57am (AEST) on Friday, and conducted extensive work to try to find the vessel with highly capable search aircraft and diverting four merchant ships. "Our response was professional and timely," he said. Despite these efforts no searching ships or aircraft ever sighted the vessel. Indonesian authorities say the death toll has risen to 36 and concede the ongoing search operation is now about recovering the dead rather than finding anyone else alive. Immigration Minister Scott Morrison called the disaster a "chilling reminder of what can occur when you put your life in the hands of criminals." He dismissed claims by some survivors that passengers were taken to the boat in trucks driven by Indonesian soldiers. "I won't give substance to a claim that's speculative," the minister said. Air Marshal Binskin said three boatloads of asylum seekers had been intercepted in the past week. The first was found on Tuesday carrying 18 people from India. They are in Darwin and expected to be sent home. Seven West Papuans who were dropped off on at an Australian island in the Torres Strait on Wednesday were returned to PNG the next day. On Thursday, 70 people from the third boat were transferred to detention on Christmas Island. Another vessel carrying 78 people was intercepted overnight Sunday, but doesn't count as a fourth boat because it was detected outside the weekly reporting period. Under the government's policy, asylum seekers are moved from Christmas Island to offshore detention facilities within 48 hours of their arrival. In the past week 128 have been sent for offshore processing - 68 to Manus Island and another 60 to Nauru. Mr Morrison said the 48 hour target was "working well" and health checks were being undertaken. But opposition immigration spokesman Tony Burke said when he was minister he was advised it would take up to 12 days for the health checks. "Some people didn't require the full level of scans ... but the 48 hour figure I just find extraordinary," Mr Burke told reporters in Sydney. If they're taking a risk with people's health, and that's a judgment call they've made, then he should be honest with the Australian people that that is what they are doing.