The director of a Mexican prison where 44 inmates were killed in a riot on Sunday has been sacked along with several other officials and 18 guards.
The officials are suspected of colluding in the escape of 30 inmates, who broke out during the riot.
The escaped prisoners all had links to the Zetas drugs gang, while most of the dead were from the rival Gulf cartel.
State governor Rodrigo Medina said the unrest, in Monterrey's Apodaca prison, was the result of "treachery".
He said no firearms had been used in the disturbance, and there was no sign that criminals had broken in to the jail to free fellow gang members.
Most victims were stabbed, strangled or beaten to death.
"It is hard for us to accept that the treachery, corruption and complicity of some can undermine the work of the good police and military who risk their lives every day for public security," Mr Medina said.
A reward of up to $775,000 (£490,000) has been offered for information leading to the capture of the fugitives.
Mr Medina said Nuevo Leon's state jails had been struggling to cope with an influx of violent criminals arrested during the military-led campaign against drug cartels.
Gang violence and break-outs are common in Mexico's notoriously overcrowded and corrupt prison system.
Nuevo Leon has been the scene of a bloody conflict between the Zetas and Gulf cartels, former allies who now fight over territory and drug-smuggling routes into the US.