Indonesian authorities say they have found the location where they believe a Boeing 737 passenger plane crashed into the sea shortly after take-off from the country’s capital Jakarta on Saturday.
The Sriwijaya Air jet was carrying 62 people when it disappeared from radars four minutes into its journey to Pontianak in West Kalimantan province.
More than 10 ships have now been deployed to the site with navy divers.
Investigators are analysing items they believe to be wreckage.
Search and rescue efforts were suspended overnight but were due to resume early on Sunday.
The aircraft is not a 737 Max, the Boeing model that was grounded from March 2019 until last December following two deadly crashes.
What happened to the aircraft?
The Sriwijaya Air passenger plane departed Jakarta airport at 14:36 local time (07:36 GMT) on Saturday.
Minutes later, at 14:40, the last contact with the plane was recorded, with the call sign SJY182, according to the transport ministry.
The usual flight time to Pontianak, in the west of the island of Borneo, is 90 minutes.
The aircraft did not send a distress signal, according to the head of national search and rescue agency Air Marshal Bagus Puruhito.
It is thought to have dropped more than 3,000m (10,000ft) in less than a minute, according to flight tracking website Flightradar24.com.
Witnesses said they had seen and heard at least one explosion.
Fisherman Solihin, who goes by one name, told the BBC Indonesian service he had witnessed a crash and his captain decided to return to land.
“The plane fell like lightning into the sea and exploded in the water,” he said. “It was pretty close to us, the shards of a kind of plywood almost hit my ship.”
A number of residents of an island near where the plane disappeared told the BBC they had found objects they thought were from the plane.
Who was on board the flight?
There were thought to be 50 passengers – including seven children and three babies – and 12 crew on board, though the plane has a capacity of 130. Everyone on board was Indonesian, officials say.
Relatives of the passengers have been waiting anxiously at the airport in Pontianak, as well as at Jakarta’s Soekarno-Hatta International Airport.
“I have four family members on the flight – my wife and my three children,” Yaman Zai told reporters through tears.
“[My wife] sent me a picture of the baby today… How could my heart not be torn into pieces?”
What do we know about the plane?
According to registration details, the plane was a 26-year-old Boeing 737-500.
It was in good condition, Sriwijaya Air chief executive Jefferson Irwin Jauwena told reporters. Take-off had been delayed for 30 minutes due to heavy rain, he said.
Sriwijaya Air, founded in 2003, is a local budget airline which flies to Indonesian and other South-East Asian destinations.
The plane went missing about 20km (12 miles) north of the capital Jakarta, not far from where another flight crashed in October 2018.
A total of 189 died when an Indonesian Lion Air flight plunged into the sea about 12 minutes after take-off from the city.
That disaster was blamed on a series of failures in the plane’s design, but also faults by the airline and the pilots.
It was one of two crashes that led regulators to pull the Boeing 737 Max from service. The model resumed passenger flights in December after a systems overhaul.
The BBC’s Jerome Wirawan in Jakarta says the latest events will bring up difficult questions and emotions in Indonesia, whose airline industry has faced intense scrutiny since the Lion Air crash.