Chile's Air Force announced Wednesday that it had located what appeared to be debris from a missing military cargo plane floating in the sea. 

The Hercules C-130 was flying from the southern Chilean city of Punta Arenas to Antarctica with 38 people on board when radio contact with it was lost on Monday.

Air Force Commander Eduardo Mosqueira told a press conference that a ship taking part in the search effort had sighted what could be part of the plane's fuel tanks.

The debris "could be part of the remains of the sponges of the internal fuel tanks of the C-130," he said.

The discovery was made 30 kilometers (18 miles) south of where the plane last made radio contact. The Air Force said the parts would be analyzed to determine if they belong to the missing plane — a process that could take up to two days.

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Chilean officials have said it's still not clear what caused the crash.

The plane disappeared over the notoriously treacherous Drake Passage, a remote stretch of ocean between the tip of South America and Antarctica.

Several countries are taking part in an extensive sea and air search, covering an area of about 400 by 450 kilometers (250 by 280 miles). 

nm/sms (AFP, EFE, Reuters)

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