Indonesian authorities say rescue teams have detected an object with “high magnetic force” at a depth of 50 to 100 metres in seas north of Bali where a submarine carrying 53 crew disappeared.
Yudo Margono, the navy’s chief of staff, said authorities hoped the unidentified object was the missing sub KRI Nanggala-402, which lost all contact with authorities on Wednesday during a torpedo drill.
Mr Margono said they were waiting for a navy ship with underwater detection facilities to arrive in the area before they could investigate further.
Military authorities said there was enough oxygen on board to last three days.
The submarine has been missing for just over 48 hours, leaving only one day to locate the men before they run out of air.
The submarine was carrying 49 crew members, a commander and three gunners, Indonesia’s Defence Ministry said.
The ageing German-made submarine was conducting a torpedo drill in waters north of Bali but failed to relay the results as expected, a navy spokesman said.
Military chief Hadi Tjahjanto said contact with the vessel was lost at 4.30am (local time) on Wednesday.
The Australian government has offered any assistance it could to the Indonesian military for its rescue operation.
“We operate very different submarines from this one, but the Australian Defence Force and Australian Defence organisation will work with defence operations in Indonesia to determine what we may be able to do,” Foreign Minister Marise Payne told the ABC’s AM program.
Fears a deep dive could cause implosion
Indonesia’s Defence Ministry said the submarine lost contact after being granted clearance to dive.
A helicopter later spotted an oil slick near the dive’s starting position.
The navy said an electrical failure might have occurred during the dive, causing the submarine to lose control and become unable to undertake emergency procedures that would have allowed it to resurface.
The missing sub can safely operate in waters up to 500 metres deep, but authorities fear a loss of power could have meant the vessel sank to a much greater depth.
If the object detected is the submarine, navy authorities suspect the crew may have deliberately released its fuel load to allow it to float after the possible loss of power.
Otherwise, they fear the sub may have sunk to a depth where it would almost certainly implode.