Forty-nine inmates died during an overnight riot in a prison in the southwestern Colombian city of Tulua, the head of the national prisons agency has said.
It is unclear what caused the riot but General Tito Castellanos, the head of the INPEC agency, told local Caracol Radio: "It is a tragic and disastrous event."
General Castellanos added that the prison had a total number of 1,267 inmates and around 30 people were injured.
Colombian President Ivan Duque, who is on a visit to Portugal, said on Twitter the incident would be investigated.
He wrote: "We regret the events in the prison in Tulua, Valle del Cauca. I am in touch with (General Tito Castellanos) and I have given instructions to carry forward investigations that allow us to clarify this terrible situation."
Two years ago, a prison riot in Colombia’s capital Bogotá left 23 prisoners dead and over 80 injured as inmates protested about health conditions amid the global outbreak of coronavirus.
Following this event, the South American country said it would release thousands of prisoners as detainees complained about crowded conditions and lack of services.
A report by international forensic experts commissioned by Human Rights Watch shows that there was intentional killing of detainees during this prison riot in March 2020.
They found that “Most of the gunshot wounds described in the autopsy reports are consistent with having been produced with the objective of killing.” The experts also said that “The autopsy reports do not record any signs of gunshot injuries carried out with the intention of solely injuring individuals instead of killing them.”
In neighbouring Ecuador, prisoners dying is commonplace and hundreds have died over the last year, in what the government there says is violence connected to drug gang competition.