An Indonesian aircraft with 189 people on board has crashed into the sea and sunk soon after taking off from the capital, Jakarta, on a domestic flight to a tin-mining region.
There was no sign of any survivors from Lion Air flight JT610, an almost new Boeing 737 MAX 8, and rescue officials said later on Monday they had recovered some human remains from the crash site, about 15km off the coast.
The plane on Monday lost contact with ground officials shortly after its pilot had asked to turn back to base, about 13 minutes after it took off, officials said.
Indonesia is one of the world's fastest-growing aviation markets, although its safety record is patchy. If all aboard have died, the crash would be the country's second-worst air disaster since 1997, industry experts said.
At least 23 government officials, four employees of state tin miner PT Timah and three employees of a Timah subsidiary were on the plane. A Lion Air official said on Italian passenger and one Indian pilot were on board.
The plane went down in waters about 30 -35 metres deep. Items such as handphones and life vests were found, along with the body parts.
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 said the aircraft had been in operation since August, was airworthy, with its pilot and co-pilot together having accumulated 11,000 hours of flying time.
The flight took off from Jakarta at around 6.20am (10.20am AEDT) and was due to have landed in Pangkal Pinang, capital of the Bangka-Belitung tin mining region, an hour later.
Distraught relatives of those on board arrived at the airport in Jakarta and Pangkal Pinang.
The head of Indonesia's transport safety committee said he hoped the cause of the crash would be determined when the plane's black boxes, as the cockpit voice recorder and data flight recorder are known, were recovered.
President Joko Widodo told a news conference authorities were focusing on the search and rescue, and he called for the country's prayers and support.
The effort to find the wreckage and retrieve the black boxes represents a major challenge for investigators in Indonesia, where an AirAsia Airbus jet crashed in the Java Sea in December 2015.
Boeing was deeply saddened by the loss, it said in a statement, and was ready to provide technical assistance for the investigation.
Data from FlightRadar24 shows the first sign of something amiss was around two minutes into the flight, when the plane had reached 2000 feet (610 m).
Then it descended more than 500 feet (152m) and veered to the left before climbing again to 5000 feet (1524m), where it stayed during most of the rest of the flight.
It began gaining speed in the final moments and reached 345 knots before data was lost when it was at 3650 feet (1113 m).
Founded in 1999, Lion Air's only fatal accident was in 2004, when an MD-82 crashed upon landing at Solo City, killing 25 of the 163 on board, the Flight Safety Foundation's Aviation Safety Network says.
© DPA 2018