Indonesian authorities have said they have located black box recorders from the Sriwijaya Air plane that crashed yesterday shortly after take-off with 62 people on board.
It comes as divers have recovered body parts, wreckage and clothing from waters off Indonesia's capital Jakarta.
The Sriwijaya Air Boeing 737-500 plunged into a steep dive about four minutes after it left Soekarno-Hatta international airport in Jakarta yesterday afternoon.
A military vessel "has found the signal from (Sriwijaya Air) SJ182" and divers had recovered parts of the plane from around 23 metres (75 feet) below the water's surface, the transport ministry said Sunday, citing Indonesia's military chief Hadi Tjahjanto.
The frantic search appeared to offer no hope of finding any survivors.
"Several body parts have been found and they've been taken to the police hospital for identification," Jakarta police spokesman Yusri Yunus told AFP.
"We don't know yet whether they're from one person. Belongings that we think are from the passengers were also found."
A child's pink trousers, a broken tyre and wheel, life jackets and suspected wreckage from the plane were also found, according to authorities and AFP reporters on the scene.
Flight SJ182 was bound for Pontianak city on Indonesia's section of Borneo island, about 90 minutes flying time over the Java Sea.
Last night, distraught relatives waited nervously for news at Pontianak airport.
The discovery of body parts and wreckage came as a flotilla of warships, helicopters and divers were deployed off the coast of the sprawling capital Sunday.
Sixty-two passengers and crew were on board the plane, all of them Indonesians, including 10 children, authorities said.
The plane crashed near popular day-trip tourist islands just off the coast, authorities said.
More than 300 personnel from search and rescue, the navy and the police were taking part in the search.
The search-and-rescue agency earlier said poor conditions were hampering the effort, but the military later said visibility had improved and the recovery operation would continue today.
Data from FlightRadar24 indicated that the plane reached an altitude of nearly 11,000 feet before dropping suddenly to 250 feet. It then lost contact with air traffic control.
The transport minister said yesterday that the jet appeared to deviate from its intended course just before it disappeared from radar.
Sriwijaya Air, which operates flights to destinations in Indonesia and Southeast Asia, has said only that it was investigating the loss of contact.
It did not immediately comment when contacted by AFP again today.
In October 2018, 189 people were killed when a Lion Air Boeing 737 MAX jet slammed into the Java Sea about 12 minutes after take-off from Jakarta on a routine one-hour flight.
That crash - and another in Ethiopia - saw Boeing hit with $2.5bn in fines over claims it defrauded regulators overseeing the 737 MAX model, which was grounded worldwide following the two deadly crashes.
The jet that went down yesterday is not a MAX model and was 26 years old, according to authorities.
"We are aware of media reports from Jakarta regarding Sriwijaya Air flight SJ-182. Our thoughts are with the crew, passengers, and their families," Boeing said in a statement.
"We are in contact with our airline customer and stand ready to support them during this difficult time."
Indonesia's aviation sector has long had a reputation for poor safety, and its airlines were once banned from entering US and European airspace.
In 2014, an AirAsia plane headed from Surabaya to Singapore crashed with the loss of 162 lives.
Domestic investigators' final report on that crash said major factors included a chronically faulty component in a rudder control system, poor maintenance, and the pilots' inadequate response.
A year later, in 2015, more than 140 people, including scores on the ground, were killed when a military plane crashed shortly after take-off in Medan on Sumatra island.