Search continues for 16 gold miners missing after mine shafts flood in Colombia

Miners and rescue workers work at the entrance to the El Tunel gold mine in Riosucio, Colombia, Wednesday, May 13, 2015. Fifteen miners are missing and feared dead after water poured into the underground shafts where they were digging early Wednesday. Authorities said the accident was likely triggered by an explosion or power outage that disabled pumps used to extract water and supply oxygen to work crews. (AP Photo/Juan Augusto Cardona) (The Associated Press)

BOGOTA, Colombia – As many as 100 rescuers have resumed the search for 16 gold miners missing feared dead after three vertical shafts flooded.

Authorities say Wednesday's accident was likely triggered by a power outage or an explosion deep underground in the mine located in northwestern Colombia.

President Juan Manuel Santos called on rescuers to "spare no effort" in the search.

But the owner of the mine fears that the 16 miners are all dead. He said it will take at least three days for rescuers to pump out excess water from an adjacent river that flooded the shafts when the accident took place.

Fatal mining accidents are common in Colombia and caused the death of 120 people last year. That's the highest tally since 2011.