Rescuers are continuing their search for two miners trapped underground in a gold mine in southern Ecuador since Friday.
They were caught 150m (490ft) underground by a cave-in that killed two other workers.
Search crew have been trying to clear debris to get to the area where the two missing miners were thought to have been working.
Ecuador's President Rafael Correa promised every effort to save them.
Rescuers said they believed they had got to within a few metres of where the trapped men were believed to have been.
"We think they may still be alive because the landslide has not affected the entire tunnel," non-renewable resources minister Carlos Parejato told the French news agency AFP.
However, there has been no sign of life from the men since the accident happened, local media reported.
The two miners confirmed dead were Walter Vera and Paul Aguirre, while the two missing men are Pedro Mendoza and Angel Vera, Walter's brother.
The collapse at the Casa Negra gold, silver and copper mine, near the town of Portovelo, is thought to have been caused by a water leak which eroded structural supports.
In Colombia, the bodies of two miners trapped for nearly a week in a mine in the central region of Boyoca were located on Monday, officials said.
The fate of miners worldwide has received renewed attention in the wake of the successful rescue of the 33 trapped miners in Chile.