Indonesian search and rescue workers believe an underwater “pinging” sound they have detected is from the black box of the Lion Air passenger jet that crashed into the sea with 189 people on board, the country’s military chief said on Wednesday.

Ground staff lost touch with flight JT610 of the Indonesian budget airline about 13 minutes after the Boeing 737 MAX 8 took off early on Monday from Jakarta, on its way to the tin-mining town of Pangkal Pinang.

There were no survivors.

Military chief Hadi Tjahjanto said that divers had already gone down to check the location from where the signal was picked up by a search and rescue team late on Tuesday but were contending with strong currents.

“We hope tonight we can drop anchor and release the ROV (remotely operated underwater vehicle) again and I am sure we will find a black box given the strong indication, and, not far from there, the main body of the plane,” Tjahjanto said.

Search and rescue agency chief Muhammad Syaugi said the current was so strong it had shifted a large ship, while efforts were further complicated because of oil and gas pipelines in the vicinity.

Syaugi said he believed the fuselage was located 400 metres northwest of where the plane had lost contact, at a depth of 32 metres. If found, the fuselage would be lifted using a crane, likely with many bodies trapped inside, he added.

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 single-aisle jet.

The plane’s black boxes, as the cockpit voice recorder and flight data recorder are known, should help explain why the almost-new jet went down minutes after take-off.

The accident is the first to be reported involving the widely sold Boeing 737 MAX 8 [Reuters]

Once retrieved, it could take up to three weeks to download their data and up to six months to analyse it, Soerjanto Tjahjono, the head of the national transport safety committee (KNKT), said.

Amid media speculation over the airworthiness of the aircraft, the transport minister suspended Lion Air’s technical director and several technicians to facilitate the crash investigation.

The suspended technicians “issued the recommendations for that flight”, the ministry said in a press release. It did not say how many technicians had been suspended.

First victim identified

Relatives are desperate to find traces of their loved ones, but so far only body parts and debris have been found.

Human remains in 53 body bags had been recovered and sent to a hospital in Jakarta, officials said.

Police officer Hudi Suryanto said forensic doctors had identified only one victim, Jannatun Cintya Dewi, 24, based on her fingerprints. She worked at the energy ministry.

Al Jazeera’s Osama bin Javaid, reporting from Jakarta, quoted medical experts as saying that it could take four to eight days to determine the DNA information retrieved from the remains and match them with the victims.

He also reported that relatives of the victims began to identify the belongings of their loved ones who perished during the flight.

According to the transport safety agency, the plane had technical problems on its previous flight on Sunday, from the city of Denpasar on the resort island of Bali, including an issue over “unreliable airspeed”.

Privately owned Lion Air, founded in 1999, said the aircraft had been in operation since August, adding that it had been airworthy and the pilot and co-pilot had 11,000 hours of flying time between them.

Lion Air chief executive Edward Sirait has acknowledged reports of technical problems with the aircraft but said maintenance had been carried out “according to procedure” before it was cleared to fly again.