Mexico City, Mexico (CNN) -- At least 141 inmates escaped Friday from a prison in Mexico's northeast border city of Nuevo Laredo, Notimex reported, citing an official.

The secretary of public security of Tamaulipas, Antonio Garza Garcia, told the state-run news agency that the inmates escaped from the Executions of Sanctions Center.

"We are working on the count but, so far, the confirmed number is 141," he said.

In addition, the prison director, Jesus Horacio Sepulveda, had disappeared, it said.

A preliminary investigation indicated that the inmates -- in collusion with prison workers -- escaped through the service entrance for vehicles belonging to prison staff members, Governor Eugenio Hernandez said.

The escape was reported after roll call was taken, at about 7 p.m., he said.

"We will have no restriction on punishing whoever has to be punished," Garza Garcia said. "We are going to act with the full weight of the law."

Security at eight other penitentiaries has been tightened, he told Radio Formula.

Tamaulipas has been a battleground for turf wars between rival drug groups, though there was no immediate indication that drug gangs were involved.