Chief of Indonesia's Lion Air flight JT610 search and rescue operations. Photograph:( Reuters )
Lion Air said human remains were collected in 24 body bags after sweeps of the site of the crash, in waters about 98 to 115 ft deep roughly 15 km off the coast to the northeast of Jakarta.
Indonesia on Tuesday stepped up a search for an airliner that plunged into the sea with all 189 aboard feared dead, deploying underwater beacons to trace its black box recorders and uncover why an almost-new plane crashed minutes after take-off.
Indonesia, one of the world's fastest-growing aviation markets, has a patchy safety record. With the now almost certain prospect of all on board having died, the crash is set to rank as the country's second-worst air disaster.
Ground staff lost contact with flight JT610 of budget airline Lion Air 13 minutes after the Boeing 737 MAX 8 aircraft took off early on Monday from the airport in Jakarta, the capital, on its way to Indonesia's tin-mining region.
"Hopefully this morning we can find the wreckage or fuselage," Soerjanto Tjahjono, the head of a national transport safety panel, told Reuters, adding that an underwater acoustic beacon was deployed to locate the main body of the plane.
The search and rescue agency added that four sonar detectors were also being used in areas where aircraft debris was found a day earlier off the shore of Karawang, West Java, and 15 vessels were scouring the sea surface.
A helicopter circled over five rubber boats carrying about 36 rescuers, as some donned rubber suits, readying to dive.
Earlier, however, Yusuf Latif, the spokesman of the national search and rescue agency, had said finding survivors "would be a miracle", judging by the condition of the recovered debris and body parts.
In a statement, Lion Air said human remains were collected in 24 body bags after sweeps of the site of the crash, in waters about 30 to 35 metres (98 to 115 ft) deep roughly 15 km (nine miles) off the coast to the northeast of Jakarta.
The bags were taken to a hospital for identification, with more expected overnight, authorities told broadcaster Metro TV.
On tarpaulins at Jakarta's port, officers laid out items retrieved from the sea, ranging from oxygen bottles to personal effects such as wallets, a mobile telephone, cash and backpacks.
Although searchers halted efforts overnight, sonar vessels and an underwater drone kept up the hunt for the wreckage, where many victims were feared trapped, officials said.
A witness in Karawang said he had heard an explosion from the beach around the time the aircraft went down.
"I thought it was thunder, but it was different from thunder - 'Boom!' - It was loud," said Dadang Hambali.
On Monday, the US National Transportation Safety Board (NTSB) and Boeing Co said they were providing assistance in the crash investigation.
(For details of search, crash inquiry, please click on)
The accident is the first to be reported involving the widely sold Boeing 737 MAX, an updated, more fuel-efficient version of the manufacturer's workhorse single-aisle jet.
Privately owned Lion Air, founded in 1999, said the aircraft, which had been in operation since August, was airworthy, with its pilot and co-pilot together having amassed 11,000 hours of flying time.
The pilot of flight JT610, which was bound for Pangkal Pinang in the Bangka-Belitung tin-mining region, had asked to return to base (RTB) shortly after take-off about 6.20 a.m., with landing set for 7.20 a.m. in the city of Pangkal Pinang.
"An RTB was requested and had been approved but we're still trying to figure out the reason," Tjahjono told reporters on Monday.
No distress signal was received from the aircraft's emergency transmitter, search and rescue agency head Muhmmad Syaugi told a news conference.
The aircraft suffered a technical problem on a flight from the resort island of Bali to Jakarta on Sunday night but it was "resolved according to procedure", Edward Sirait, chief executive of Lion Air Group, told reporters.
Sirait declined to specify the nature of the issue but said none of the airline's other aircraft of that model had the same problem. Lion had operated 11 Boeing 737 MAX 8s and it had no plan to ground the rest of them, he said.
Indonesia's worst air disaster was in 1997, when a Garuda Indonesia A300 crashed in the city of Medan, killing 234 people.