He lost contact about 95 kilometers north of Bali while participating in a torpedo training exercise.
The Indonesian armed forces reported Wednesday that they are searching for a missing submarine near the island of Bali with 53 people on board.
The chief of the armed forces, Hadi Tjahjanto, said that KRI Nanggala 402 participated in a torpedo training exercise at a depth of around 700 meters when he stopped making a planned call.
The submarine is believed to have disappeared at sea about 95 kilometers north of Bali, according to Tjahjanto, adding that the Navy sent warships and appealed to Singapore and Australia, which have submarine rescue ships, for help. Contact with the vessel was lost at 4:30 am (local time) this Wednesday.
The Defense Ministry found an oil spill at the site where the Indonesian submarine lost contact. A ministry spokesman said a press conference would be held to provide more information on the search from Bali on Thursday.
According to some reports, the connection was lost after everyone got clearance to drown in deep water.
Military analyst Soleman Ponto said it would be too early to make a final decision on the fate of the submarine. We still do not know if the communication equipment was broken or the submarine sank. He said We would have to wait at least three days.
In the past, Indonesia has operated a fleet of 12 submarines purchased from the Soviet Union to patrol the waters of its vast island.
The lost ship is one of five currently operated by the Southeast Asian country. According to the Reuters news agency, it was made in the late 1970s and underwent a two-year remodel in South Korea that was completed in 2012.
Indonesia is trying to improve its defense capabilities. However, some of its equipment that is still in service is old, and there have been fatal accidents in recent years involving, in particular, military transport aircraft.
An Indonesian Air Force carrier plane smashed into a hill during a training practice in the Papua province in 2016. As a result, all 13 people on board were killed.
While in 2015, more than 100 people were killed in an accident involving an Indonesian military transport plane that crashed in a northern residential area two minutes after takeoff.