The miners, two Canadians, two Peruvians and a native Colombian, worked for Geo Explorer and were kidnapped from Bolivar province Friday by a group of 20 to 25 leftist militants, Colombia Reports said Monday.
Santos has ordered special forces into the area to help with the investigation and the government has offered a $50,000 reward for information on the kidnappers.
Santos said the militants are believed to belong to a guerrilla group calling itself the ELN, or the National Liberation Army.
Ray Liotta sues skin care company over use of likeness
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