Rescuers lay out body bags containing human remains recovered from the crash site of Sriwijaya Air flight SJ 182 at the port in Jakarta, Indonesia on Sunday, following the Saturday crash of the airline’s Boeing 737-500 aircraft into the Java Sea minutes after takeoff. Indonesia National Transport Safety Committee chief Soerjanto Tjahjono said the locations of Flight SJ 182’s two black boxes have been identified. Photo: AFP

Indonesian divers returned Tuesday to a wreckage-littered seabed off Jakarta in their hunt for the black boxes that will likely be key to unlocking the mystery of why a passenger jet carrying 62 people fell from the sky.

Some 3,600 personnel are taking part in the recovery effort, assisted by dozens of boats and helicopters flying over small islands off the capital's coast.

Underwater images from Indonesia's navy showed divers plumbing the murky depths as they combed through twisted wreckage from the Sriwijaya Air Boeing 737-500, which plunged about 3,000 meters in less than a minute before ­slamming into the Java Sea ­on Saturday.

Authorities have so far been unable to explain why the 26-year-old plane crashed just four minutes after takeoff.

But they say they have the approximate location of the black boxes after picking up signals from the devices, which record information about the speed, altitude and direction of the plane as well as flight crew conversations.

Black box data helps explain nearly 90 percent of all crashes, according to aviation experts.

But the boxes could be hidden under layers of mud or plane wreckage in waters about 23 meters deep, and divers have to grapple with a strong current and poor weather.

"They've got to go through garbage and other debris [on the seafloor] and the mud and visibility are also a challenge," Yusuf Latif, a spokesman for Indonesia's search-and-rescue agency, said Tuesday.