The UN has called for investigation into a prison riot in Mexico that left more than a dozen people dead.
The death toll rose to 17 on Wednesday night following clashes inside Cadereyta jail in Nuevo Leon state earlier in the week.
The UN cited other recent prison revolts as a reason for a “complete and exhaustive” report .
State authorities said they are open to cooperating with human rights organisations.
They previously said lethal force was needed to regain full control of the facility, near Monterrey.
About 250 inmates battled security forces during the disturbance, local media report.
A UN statement urged authorities “to clarify the tragedy that has occurred and to grant justice to the victims and their families”, according to El Universal newspaper.
“Do you want somebody responsible? I am responsible,” state security spokesperson Aldo Fasci told reporters.
He said attempts to mediate with inmates who took three guards hostage had failed.
However, he insisted no direct orders were given to start shooting. Officers were following protocol, he said.
He also said a police officer had a lung seriously injured when a prisoner attacked him with a “rod”.
The UN statement referenced a 2016 a riot at Topo Chico prison, which left 49 people dead, and another violent outbreak at Apodaca prison in 2012, where 44 people died. Both prisons are in Nuevo Leon state.
Mexican prisons are often criticised for overcrowding and an inability to tackle violence between rival gangs.