At least 11 members of a group formed by former FARC rebels who reject a peace deal were killed in combat with soldiers in Colombia's jungle south, the army said on Tuesday.
The confrontation in a rural area of Puerto Leguizamo municipality, in the province of Putumayo near the border with Ecuador and Peru, took place on Monday.
The region has extensive cultivations of coca, the base ingredient in cocaine, and drug-producing laboratories, security sources say.
Four fighters from the group -- Segunda Marquetalia -- were also captured.
The Revolutionary Armed Forces of Colombia (FARC) officially demobilized under a 2016 accord with the government, but some members, including former commanders, reject the deal and continue to engage in drug trafficking and illegal mining.
The two dissident groups -- which count a total of about 2,400 combatants -- are considered a top security threat by Colombian authorities, who accuse them of massacring civilians and murdering human rights activists.
Colombia's nearly six decades of internal conflict have killed some 260,000 people.
(Reporting by Luis Jaime Acosta; Writing by Julia Symmes Cobb; Editing by Jonathan Oatis)