The Boeing 737-500 with 62 passengers and crew was headed to Pontianak in West Kalimantan before it disappeared on Saturday from radar screens four minutes after takeoff.
The crash is the first major airline incident in Indonesia since the crash of a Lion Air Boeing 737 Max in 2018 that killed all 189 passengers and crew. That plane also plunged into the Java Sea soon after takeoff from Soekarno-Hatta International Airport.
“We have detected signals in two points. This could be the black box,” Bagus Puruhito, chief of Indonesia’s search and rescue agency, told reporters aboard a military ship.
Indonesian Navy official Wahyudin Arif told iNEWS they had found suspected pieces of the plane fuselage of about one metre (three feet) in length, part of a tyre and human body parts.
Media reports said body parts had been taken to a police hospital for identification.
Flight SJ 182 had 12 crew and 50 passengers on board, all Indonesians and including seven children and three babies.
“I am optimistic we will find (the plane) soon,” Henri Alfiandi, an assistant to the chief of staff of the Indonesian Air Force, told a news briefing.
President Joko Widodo, speaking at the palace in Bogor, expressed “deep condolences” over the disaster and urged the public to pray the missing people could be found.
