Relatives of prisoners in a Mexican jail have turned on authorities for failing to accurately identify most of the 44 inmates who were killed in a mass fight between rival gangs.
Fighting broke out between members of the Gulf and Zetas cartels in the prison outside Monterrey in northeast Mexico.
Victims were beaten, knifed and stoned during the riot on Sunday, authorities said.
The fight broke out in a high-security section of the state prison between the inmates of two cell blocks, each containing 750 prisoners.
Nuevo Leon state public security spokesman Jorge Domene Zambrano said the fight may have been planned and used as a cover for a prison break. Some prisoners are missing but it is not known how many.
Families of inmates staged a protest outside the prison to complain about a lack of information on prisoners who died or were injured in the fight. Less than a quarter of the dead have been named.