IE 11 is not supported. For an optimal experience visit our site on another browser.

Indonesian submarine: 53 sailors presumed dead as navy says vessel sunk

"We have now moved from the 'sub miss' phase to 'sub sunk,'" Indonesian Navy Chief of Staff Adm. Yudo Margono told a news conference.

There is little hope of finding survivors from a missing Indonesian submarine, the country's navy said Saturday, after officials declared the vessel had sunk.

"We have now moved from the 'sub miss' phase to 'sub sunk,'" Indonesian navy Chief of Staff Adm. Yudo Margono told a news conference, where he showed debris including a torpedo straightener and Islamic prayer rugs from the submarine.

"We are still carrying out the search ... the depth of the sea we have detected is at 850 meters (2,790 feet), which is very tricky and presents many difficulties," he said.

Earlier this week the navy said that it thought the vessel had sunk to a depth of 600-700 meters (2,000-2,300 feet), much deeper than its collapse depth of 200 meters (655 feet), at which point the water pressure would be greater than the hull could withstand.

Oxygen supplies for the 53 crew members on board the German-built "KRI Nanggala 402" had also likely now run out, Margono added.

Download the NBC News app for breaking news and politics

His comments came shortly after a U.S. reconnaissance plane, P-8 Poseidon, landed in the southeast Asian country to join 20 Indonesian ships, a sonar-equipped Australian warship and four Indonesian aircraft in the desperate search for the vessel.

Singaporean rescue ships were also expected later Saturday, while Malaysian rescue vessels were due to arrive Sunday, bolstering the underwater hunt, Indonesia military spokesperson Djawara Whimbo said ahead of the press conference.

He added that they would keep searching for the vessel "until we find it and whatever the result."

The submarine lost contact Wednesday after its last reported dive about 60 miles north of the vacation-island of Bali. It was participating in a training exercise, rehearsing for torpedo drills, when it missed a scheduled reporting call.

The cause of the disappearance is still uncertain. The navy said earlier this week that an electrical failure could have left the vessel unable to execute emergency procedures to resurface.

Hopes were briefly raised Friday when an Indonesian hydrographic vessel detected an unidentified object exhibiting high magnetism at a depth of 50 to 100 meters (165 to 330 feet) but no repeat detection was successful.

The submarine has been in service in Indonesia since 1981 and was carrying 49 crew members and three gunners as well as its commander, the Indonesian Defense Ministry said.

Indonesia, the world's largest archipelago nation with more than 17,000 islands, has faced growing challenges to its maritime claims in recent years, including numerous incidents involving Chinese vessels.

The country is no stranger to disaster. Dozens were killed and thousands displaced by landslides and flash floods in eastern Indonesia in April. A passenger plane with more than 60 people on board also crashed over the Java Sea in January, shortly after taking off from Indonesia’s capital, Jakarta.