BOGOTA, Colombia—President Juan Manuel Santos says authorities in Colombia have captured three suspected rebels who formed part of the group that kidnapped five gold prospectors doing exploratory drilling for a Canadian company in the country's north.

Santos said in a press conference Sunday that two of the alleged National Liberation Army, or ELN, rebels are minors and have been turned over to the Colombian Institute of Family Welfare.

While the kidnapped prospectors—a Canadian, two Peruvians and two Colombians—are still in rebels hands, Colombia's president said the three detained suspects belonged to the group that carried out the abduction Friday and that authorities are pursuing the rest of the group.

Toronto-based Braeval Mining Corp. said the three company employees and two consultants were working at its Snow Mine gold and silver project.

The leftist ELN is Colombia's second-largest insurgency, much smaller than the Revolutionary Armed Forces of Colombia.