Colombian troops killed 14 FARC guerrillas in fighting over the weekend, the head of the armed forces said Monday.
The spike in military activity comes with government and rebel negotiators poised to resume peace talks Tuesday after a pause of more than a month for national elections.
General Juan Pablo Rodriguez, head of the armed forces, told reporters the fighting was part of a "sustained and continuous operation" against the FARC in northwestern Colombia.
The FARC, Colombia's largest guerrilla group, has been holding peace talks with the government since November 2012, but there has been no ceasefire in Latin America's oldest armed conflict.
President Juan Manuel Santos was re-elected June 15 on a peace platform, raising optimism about the prospects for a negotiated solution.
But Santos has vowed to keep the military pressure on the FARC until a comprehensive peace agreement is reached.
The weekend fighting "shows that the military forces and police are on the offensive," Rodriguez said.