Soldiers fought Revolutionary Armed Forces of Colombia (Farc) rebels in the central province of Cundinamarca, killing 10 and capturing another eight. [break]
Among those taken was a leader known by the alias "El Negro Antonio", whom authorities have been seeking for well over a decade.
One soldier was killed in the combat and a kidnap victim rescued.
"El Negro Antonio" is a Farc guerrilla with 33 arrest warrants outstanding against him.
The operation took place in the mountain range of Sumapaz in Cundinamarca province.
It is a severe setback for the Farc, not just because of the number of rebels killed and captured, but because it hinders its plans to reopen a movement corridor into the capital, Bogota.
It was along this corridor that El Negro Antonio used to move kidnap victims out of Bogota and into the rebel-controlled lowland jungles.
Under their new leader Alfonso Cano, the Farc rebels have been seeking to retake the initiative snatched from them over the last five years by the US-backed military.
The rebels are seeking to bring their four-decade-old war back into the cities, particularly Bogota, where their attacks have far greater impact than in the countryside.
Road to peace for Colombia’s FARC