More than 40 inmates at a detention center in northern Mexico were killed last weekend and another 26 escaped. The United Nations said the attacks were organized by criminal drug gangs and most of those who escaped were accused of "grave crimes."
Ravina Shamdasani, a spokeswoman for the U.N. Office of High Commissioner for Human Rights, called on the Mexico government to investigate the incident.
"Those responsible, including relevant prison authorities, must be brought to justice and all necessary measures taken to prevent such attacks from recurring," she said in a statement.
OHCHR said gang warfare was problematic in Mexican prisons and expressed concern about detention policies of Latin American governments in general.
Last week a fire at a Honduran prison resulted in the deaths of 358 people.
"The Comayagua prison in Honduras, built for 250 detainees was reportedly holding more than 800 when the fire broke out," the office said in a statement. "As many as 3,000 inmates were being held in the detention center in Mexico at the time of the riot, although it was designed for half that number."
Prison guards were suspected of aiding in the weekend escape.