Updated

Argentina's navy says that a U.S. aircraft searching for a missing submarine with 44 crew members aboard has spotted a white flare, but it's unlikely to be from the sub.

Navy spokesman Enrique Balbi said Tuesday that the ARA San Juan carries red and green flares, but authorities will still try to identify the origin of the signals.

Balbi also said that a life raft that doesn't belong to the submarine was found in the search area.

The sub went missing Wednesday as it journeyed from the extreme southern port of Ushuaia to the coastal city of Mar del Plata. International vessels and aircraft have joined the search.

The submarine only has enough oxygen to last seven days if submerged.