Colombia's Roman Catholic Church on Friday denounced a rebel murder of a priest, which the UN called a "warcrime."
Francisco Montoya, 45, was kidnapped by the Revolutionary Armed Forces of Colombia, known by its Spanish initials as FARC, which on Thursday took responsibility for the murder, according to a church commission.
"The information that the guerrilla group gave the commission is that they had shot him and would not hand over his body, which they had buried," according to Alonso Llano, bishop of Istmina Tado, who said he did not know when the murder had occurred.
Montoya was kidnapped in Novita, in Choco, one of Colombia's poorest provinces, 650km northwest of Bogota. The Pacific coast had until recently largely been spared the violence of FARC's 40-year battle against the government.
The commission did not mention motives for the killing.
The Colombia office UN of the High Commissioner for Human Rights demanded that the FARC make a public statement and allow the body to be recovered.
"It is a warcrime and it makes clear the perpetrators' deep disrespect for the fundamental rights of the civilian population," the UN office said in a statement.
"It is a tragedy," Colombian President Alvaro Uribe said.
Two weeks ago, rebels of the National Liberation Army, known by its Spanish initials as ELN, clashed with right-wing paramilitary fighters near the place where Montoya had been kidnapped.
ELN is the smaller of Colombia's rebel bands, with 4,500 armed fighters.