Colombian President Juan Manuel Santos has suspended two-year peace talks with the country's largest rebel group, the FARC, as the military investigated the suspected abduction of a general and two others.
"Tomorrow, peace negotiators were traveling for a new round of talks in Havana," Santos said at a press conference.
"I will tell the negotiators not to travel, and the negotiations are suspended until there is clarification and these people are released."
The decision to suspend the talks came during an emergency meeting between the president and the top military leaders that was called after the general's disappearance was announced.
General Ruben Alzate lost contact on Sunday with ground forces in Quibdo in the southwest, where the FARC is active, the president had said earlier.
Also missing were army corporal Jorge Rodriguez and lawyer Gloria Urrego, an official with the army's Titan task force, operating in the area, Defense Minister Juan Carlos Pinzon added.
"It is totally unacceptable abduction. We have information that gives us certainty that it was the FARC," Santos said after the emergency meeting.
The president emphasized the FARC would be held responsible for the life and safety of the three hostages and demanded their release "soon."
He has ordered Pinzon to travel to the isolated Choco department town to lead the investigation into the presumed abductions.
Alzate was surprised by men with rifles when he arrived on a small boat in the village of Las Mercedes, in the rural Quidbo region, mid-afternoon Sunday, to review a civilian energy project.
The soldier piloting the boat was able to escape, and he returned to Quidbo where he reported what happened to commanders.
"We do not know the personal or intelligence reasons why security protocols to protect the general were not followed," Pinzon said, adding that the Red Cross has been contacted to help negotiate the release of the three.
Founded in 1964, the FARC today counts about 8,000 fighters and is the largest of the guerrilla groups waging Latin America's longest-running armed conflict.
The FARC has been in dialogue with Colombian government negotiators attempting to broker a peace deal to end the five-decade-long fight.
The talks, which began in 2012, are days away from marking their second anniversary, and had so far made more progress toward ending the conflict than any previous peace effort.
There has not been an accompanying bilateral ceasefire during the negotiations.
However, in 2012, the rebel group pledged to no longer kidnap civilians for ransom. The guerrillas reserved the right to take police and soldiers captive, considering them prisoners of war.