A group of 17 inmates fled Thursday from the jail in the north-eastern Mexican city of Reynosa with the help of four guards, jail director Carlos Hernandez said, dpa reported.
Hernandez said the escape happened overnight, and noted that the four guards who allegedly helped the inmates to flee remained missing.
The head of the jail in the state of Tamaulipas declined to say who the inmates were and of what crimes they had been convicted.
Local and federal security forces were on alert in an effort to find the runaway convicts.