Indonesian divers on Monday were still searching for the black boxes of a crashed jet that nosedived into the Java Sea on Saturday with 62 people on board.
A 2,500-strong rescue team had uncovered parts of the Sriwijaya Air Boeing 737 and some human remains on Sunday, AP reported, but no sign of survivors.
Authorities have said signals from the boxes containing the cockpit voice and flight data recorders were detected just north of Jakarta's coast.
Officials said they have marked a location where the sounds were being emitted from the black boxes, which detached from the tail of the aircraft when it plummeted into the sea.
The cockpit voice recorder holds conversations between pilots, and the data recorder tracks electronic information such as airspeed, altitude and vertical acceleration.
When found, they will be transported to port and handed to the National Transportation Safety Committee overseeing the crash investigation.
"We have located the position of the black boxes," said Soerjanto Tjahjanto, head of a committee in the Ministry of Transport.
"Divers will start looking for them and I hope it won't take long to recover them".
Flight SJ182 lost contact with air traffic controllers on Saturday, minutes after taking off from Indonesia's capital in heavy rain.
Transportation Minister Budi Karya Sumadi said on Saturday that the flight was delayed for an hour before it took off at 2.36 pm local time (8.36 am CET).
The Boeing 737-500 disappeared from radar screens four minutes later after the pilot contacted air traffic control to ascend to an altitude of 8,839 meters, he said.
Flight tracker website FlightRadar24 showed SJ182 losing more than 10,000 feet of altitude in under a minute.
The plane was on a 90-minute flight from Jakarta to Pontianak, the capital of West Kalimantan province on Indonesia’s Borneo island, when it disappeared.
Hopes of finding survivors dashed
Indonesian President Joko Widodo expressed "his deep condolences" and called on his fellow citizens to "pray together for the victims to be found".
But relatives' hopes of finding survivors from the flight to Pontianak were dwindling by Sunday.
Among the missing were a newly-married couple, Ihsan Adhlan Haki and his wife Putri.
"He called me to tell me that the flight was delayed due to bad weather," said Arwin, the groom's brother, from Pontianak where a ceremony was planned for the couple.
"That was the last time I had contact with him".
Among the passengers were also Beben Sofian, a 59-year-old Indonesian woman, and her husband Dan Razanah, 58.
"They made a selfie and sent it to their children before taking off," their nephew Hendra told AFP.
Fifty passengers, including ten children, in addition to the twelve crew members, all Indonesians, were on board the plane.
Search and rescue operation launched
A dozen vessels, including four warships, were deployed on Saturday centred between Lancang island and Laki island, part of the Thousand Islands chain just north of Jakarta, Sumadi said.
A commander of one of the search-and-rescue ships who goes by a single name, Eko, said that fishermen found cables and pieces of metal in the water.
'Sound of thunder'
"The fishermen told us that they found them shortly after they heard an explosion like the sound of thunder," Eko said.
Solihin, 22, a fisherman from Lancang Island, said he and two other fishermen heard an explosion around 30 metres from them.
"We thought it was a bomb or a tsunami since after that we saw the big splash from the water after the explosion. It was raining heavily and the weather was so bad. So it is difficult to see around clearly.
"But we can see the splash and a big wave after the sounds. We were very shocked and directly saw the plane debris and the fuel around our boat," he said.
Sriwijaya Air President Director Jefferson Irwin Jauwena told reporters that the plane had previously flown to Pontianak and Pangkal Pinang city on the same day.
"Maintenance report said everything went well and airworthy," Jauwena told a news conference. He said the plane was delayed due to bad weather, not because of any damage.
It was raining at Jakarta’s Soekarno-Hatta International Airport when the plane took off for Pontianak, around 740 kilometres (460 miles) away.
Chicago-based Boeing said on its Twitter feed on Saturday that it was aware of the incident. It said it was closely monitoring the situation and “working to gather more information.”
The twin-engine, single-aisle Boeing 737 is one of the world’s most popular planes for short and medium-haul flights. The 737-500 is a shorter version of the widely used 737 model. Airlines began using this type of plane in the 1990s, with production ending two decades ago.
Discount carrier Sriwijaya began operations in 2003 and flies to more than 50 destinations in Indonesia and a handful of nearby countries. Its fleet includes a variety of 737 variants as well as the regional ATR 72 twin-engine turboprop plane.
Indonesia, the world’s largest archipelago nation, with more than 260 million people, has been plagued by transportation accidents on land, sea, and air because of overcrowding on ferries, ageing infrastructure, and poorly enforced safety standards.
In October 2018, a Boeing 737 MAX 8 jet operated by Lion Air plunged into the Java Sea just minutes after taking off from Jakarta, killing all 189 people on board. It was the worst airline disaster in Indonesia since 1997 when 234 people were killed on a Garuda flight near Medan on Sumatra island. In December 2014, an AirAsia flight from Surabaya to Singapore plunged into the sea, killing 162 people.
Indonesian airlines were previously banned from flying to the United States and the European Union for not meeting international safety standards. Both have since lifted the ban, citing improvement in aviation safety and greater compliance with international standards.