In total, up to December 20, a total 105 killings had been registered, it said. Another 11 were being verified.
Colombia's government, which had a different tally of such deaths, denied there was a systematic pattern to the murders.
His defence minister, Luis Carlos Villegas, said on Sunday that "most" of the murders were over turf disputes and "struggles over illicit income."
But the UN statement expressed concern at the killings, and said agitation for human rights appeared to be the determining motive for the violence.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)