Argentina says it’s accelerating the search for a submarine that has been lost in the South Atlantic for eight days amid growing fears for its 44 crew members.

The navy says an explosion occurred near the time and place where the sub went missing on Nov. 15. That’s led some to give up hope.

But spokesman Enrique Balbi said Friday that the international search continues. He said Russia is sending an Antonov transport aircraft. And a ship is being adapted in the southern Patagonian port of Comodoro Rivadavia to carry a U.S. Navy submarine rescue chamber to the area.

Argentine navy officials worry that even if the ARA San Juan is intact but submerged, its crew may be running out of oxygen.

(AP)