The search for a missing Argentinian submarine that has been lost for 15 days will continue but the rescue element of the mission for 44 crew members on board has ended, the country's navy says.
Spokesman Enrique Balbi said the rescue mission "extended for more than twice what is estimated for a rescue".
The navy said an explosion occurred near the time and place where the ARA San Juan submarine went missing on November 15.
Hopes for survivors had already dimmed because experts said the crew only had enough oxygen to last up to 10 days if the submarine remained intact under the sea.
More than a dozen countries have been searching for the missing vessel.
The navy has said the vessel's captain reported that water entered the snorkel and caused one of the submarine's batteries to short circuit.
The captain later communicated by satellite phone that the problem had been contained, the navy says. Some hours later, the explosion was detected.
A navy spokesman said this week that the blast could have been triggered by a "concentration of hydrogen" caused by the battery problem reported by the captain.
The San Juan, a German-built diesel-electric TR-1700 class submarine, was commissioned in the 1980s and most recently refitted in 2014.
Some family members have also denounced the age and condition of the vessel.
President Mauricio Macri has promised a full investigation.