BALI: Debris has been recovered from a missing Indonesian submarine, the country’s navy said Saturday, suggesting that the stricken vessel could have broken apart after sinking with 53 crew aboard. The development dashed already slim hopes of rescuing the sailors alive after their oxygen reserves were understood to have run out earlier in the day.

Warships, planes and hundreds of military personnel have been searching for the KRI Nanggala 402 since it disappeared off the coast of Bali early Wednesday.

Authorities earlier said the German-built craft was equipped with enough oxygen for only three days after losing power.

That deadline passed Saturday morning.

The navy’s chief Yudo Margono said a search party had recovered fragments from the submarine including items from inside the vessel — pointing to a catastrophic accident.

“We have raised the status from submiss to subsunk,” he told reporters, adding that the retrieved items could not have come from another vessel.

“(The items) would not have come outside the submarine if there was no external pressure or without damage to its torpedo launcher.”

Navy officials displayed several items including a piece of its torpedo system and a bottle of grease used to lubricate a submarine’s periscope.

They also found a prayer mat commonly used by Muslims. Indonesia is the world’s most populous Muslim-majority nation.

Margono said the hunt for the submarine — and sailors — would continue, but warned that deep waters made the recovery effort “very risky and difficult”.

“We don’t know about the victims’ condition because we haven’t found any of them. So we can’t speculate,” he said in response to questions about the possibility of survivors.

“But with the (discovery) of these items, you can make your own conclusion.”

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

An oil spill spotted where the submarine was thought to have submerged pointed to possible fuel-tank damage, fanning fears of a deadly disaster.

There were concerns that the submarine could have been crushed by water pressure if it sank to depths of more than 700 metres (2,300 feet) — well below what it was built to withstand.

The vessel was scheduled to conduct the training exercises when it asked for permission to dive. It lost contact shortly after.

Authorities have not offered possible explanations for the submarine’s sudden disappearance or commented on questions about whether the decades-old vessel was overloaded.

The military has said the submarine, delivered to Indonesia in 1981, was seaworthy.