A man reads a newspaper that shows candidates Gustavo Petro and Ivan Duque go to the second round of Colombia's presidential election, in Bogota. Picture: Jaime Saldarriaga/Reuters

Bogota - The Colombian army killed 11 suspected dissidents from the former guerrilla group FARC and captured two others on Monday, the Defence Ministry said.

The military operation was carried out near Montanita in southern Caqueta department. It came one day after Sunday's presidential elections, which were won by Ivan Duque, a right-wing senator critical of the government's 2016 peace deal with FARC.

About 7 000 FARC fighters handed over their weapons last year, but an estimated 1,200 others did not join the peace process and remain active in the countryside.

The group that the Montanita dissidents belonged to was reportedly planning attacks and had issued threats against officials and an electricity company.

Two members of the group - one of them a minor - were injured and captured by the army before being given medical care.

Colombia's peace deal with FARC followed a 52-year conflict involving several leftist guerrilla groups, the army and right-wing paramilitary groups. More than 220,000 people have been killed and 7 million displaced.

Sunday's elections left the peace process hanging in the balance as Duque prepares to face off against leftist Gustavo Petro in a run-off on June 17.

Petro's victory would guarantee continuity of the peace process. Duque has pledged to modify it, sparking concern that many of the demobilized FARC fighters might join the dissidents or other armed groups.