Uribe said in a statement that among the dead were six children, CNN reported Thursday.
The bodies were discovered Wednesday about 50 miles from the city of Tumaco near Colombia's border with Ecuador. Uribe said the attack by unidentified gunmen took place near a location where coca is grown to be processed into cocaine.
Human-rights experts have been asked to join the investigation into the mass killing and the Colombian government has offered a reward for information that brings about the capture of those responsible.
The Colombian Defense Ministry said in a statement that investigators were still attempting to determine why the attack took place and what group may be responsible.
CNN said in February guerrillas with the Marxist Revolutionary Armed Forces of Colombia took responsibility for killing an unspecified number of Indians suspected of working with the government.