Indonesian officials say debris from a missing submarine was found after the vessel sank as hopes of rescuing 53 sailors on board faded on Saturday.

The items located included a bottle of lubricant and a device that protects a torpedo, Air Marshall Hadi Tjahjanto said.

“The objects found near the last location of the submarine are believed to be parts of the submarine,” he said. “These objects would have never got out of the submarine unless there was pressure.”

The submarine – one of five in Indonesia’s fleet – disappeared on Wednesday during live torpedo training exercises off the Indonesian holiday island of Bali.

Navy chief Yudo Margono said on Saturday that rescuers found several items, including parts of a torpedo straightener, a grease bottle believed to be used to oil the periscope, and prayer rugs from the submarine.

“With the authentic evidence we found believed to be from the submarine, we have now moved from the sub miss phase to sub sunk,” Margono said.

Indonesia earlier considered the submarine that disappeared off Bali as just missing. But now officials declared the submarine sank.

Authorities said it was unlikely that there was an explosion on board the submarine, Al Jazeera’s Jessica Washington reported from the Indonesian capital Jakarta.

“In that event [an explosion], they would have heard it by now at this stage,” she said, adding that authorities were still exploring the possibilities for medical evacuations.

No sign of life

Officials also said the oxygen supply for its 53 crew ran out early on Saturday.

Margono said a scan had detected the submarine at 850 metres (2,788 feet), well beyond its survivable limits. The submarine is designed to withstand a depth of up to 500 metres (1,640 feet).

“If it’s an explosion it will be in pieces. The cracks happened gradually in some parts when it went down from 300 metres to 400 metres to 500 metres … If there was an explosion, it would be heard by the sonar,” said Margono, adding no bodies were found so far.

The military said it was preparing “to evacuate” the vessel.

“The submarine is found at a depth that is far beyond the crush depth of the boat. There’ll be no survivors at all, assuming that none of those on board managed to escape before it fell below the crush depth,” said Collin Koh, a research fellow at the S Rajaratnam School of International Studies in Singapore who specialises in naval affairs and maritime security.

“The evacuation they’re talking about, I surmise they’re referring likely to the eventual retrieval of the debris or whatever is left of the submarine that can be salvaged, with the hope of at least retrieving the remains of the crew,” Koh told Al Jazeera.

There have been no signs of life from the submarine, but family members have held out hope.

Berda Asmara, the wife of Second Sergeant Guntur Ari Prasetya, said she is still optimistic that her husband survived.

“Nothing is certain yet … The important thing is that we don’t stop praying and hopefully everyone will come home safely and in good health,” she told Al Jazeera. (Al Jazeera.)

•PHOTO: Indonesian Navy's KRI Oswald Siahaan-354 leaves the Tanjung Wangi port as the search continues for the missing KRI Nanggala-402 submarine in Banyuwangi, East Java Province Indonesia, April 24, 2021 [Ajeng Dinar Ulfiana/REUTERS]

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