Indonesian authorities have retrieved a black box from the Sriwijaya Air plane that crashed into the Java Sea last weekend, KompasTV reported on Tuesday, showing footage of the recording device being loaded onto a ship. The black box was being transported to Jakarta port, the television reports said. Initial findings by Indonesia's National Transportation Safety Committee (KNKT) showed a jet engine was running when it hit the water, based on damage seen on parts retrieved from the sea. They are likely to be crucial to understanding what happened to Sriwijaya Air Flight 182. Divers on Sunday located parts of the wreckage of the Boeing 737-500 at a depth of 23 metres in the Java Sea, a day after the aircraft with 62 people on board crashed shortly after take-off from Jakarta. “We received reports from the diver team that the visibility in the water is good and clear, allowing the discovery of some parts of the plane,” Air Chief Marshal Hadi Tjahjanto said. “We are sure that is the point where the plane crashed.” He said the objects included broken pieces of fuselage with aircraft registration parts. Earlier, rescuers found human remains, pieces of clothing and scraps of metal. The debris from Flight 182 was found after sonar equipment on a navy ship detected a signal from the aircraft. The signal was at the co-ordinates from the last contact made by the pilots before the plane went missing. It is unclear what caused the crash. There was no sign of survivors. “I represent the government and all Indonesians in expressing my deep condolences for this tragedy,” Indonesian President Joko Widodo said. He said he had asked the National Transport Safety Committee to conduct an investigation. Leaders around the world extended their sympathies over the tragedy. On Sunday, Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the UAE Armed Forces, offered his condolences, saying "the victims and their families remain in our hearts and prayers". Fishermen in the area between Lancang and Laki islands, part of an archipelago around Thousand Islands north of Jakarta’s coast, reported hearing an explosion at about 2.30pm local time on Saturday. “We heard something explode. We thought it was a bomb or a tsunami since, after that, we saw the big splash from the water,” Solihin, who goes by one name, told The Associated Press. “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.” Transport Minister Budi Karya Sumadi said Flight 182 was delayed for an hour before it took off at 2.36pm. It disappeared from radar four minutes later, after the pilot contacted air traffic control to ascend to an altitude of 29,000 feet, he said. There were 62 people on board, including seven children and three babies. "We are aware of media reports from Jakarta regarding Sriwijaya Air flight SJ-182," Boeing said. "Our thoughts are with the crew, passengers and their families. We are in contact with our airline customer and stand ready to support them during this difficult time." The authorities set up two crisis centres. Families gathered to wait for news of their loved ones. On social media, people began circulating the flight manifesto with photos and videos of those who were listed as passengers. One video shows a woman with her children waving goodbye while walking through the airport. The president director of Sriwijaya Air, Jefferson Irwin Jauwena, said the plane, which was 26 years old and was previously used by airlines in the US, was airworthy. He told reporters on Saturday that the plane flew to Pontianak and Pangkal Pinang city on the same day. “Maintenance report said everything went well and airworthy,” Mr Jauwena said. He said the plane was delayed owing to bad weather, not because of any damage. 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. The plane involved in Saturday’s incident did not have the automated flight-control system that played a role in the Lion Air crash and another crash of a 737 MAX 8 jet in Ethiopia five months later, leading to the grounding of the aircraft model for 20 months. The Lion Air crash was Indonesia’s worst airline disaster since 1997, when 234 people were killed on a Garuda airlines flight near Medan on Sumatra island. In December 2014, an AirAsia flight from the Indonesian city of Surabaya to Singapore plunged into the sea, killing 162 people. Sriwijaya Air has experienced several minor incidents in the past. A farmer was killed in 2008 when an arriving plane went off the runway because of a hydraulic issue. The US banned Indonesian carriers from operating in the country in 2007, but reversed the decision in 2016, citing improvements in compliance with international aviation standards. The EU has previously had similar bans, lifting them in June 2018.