REYNOSA, Tamaulipas, Mexico – State security officials in Reynosa are making staff changes at a prison, after a tunnel was discovered.

We’re told the tunnel was 1,000 feet long and ran from the main prison to the rear of the facility. State police searched the prison after they found the tunnel on Wednesday. They provided a video showing evidence of a sophisticated tunnel, which showed signs of planning by the responsible party.

There’s no word yet if any arrests or other discoveries were made. Officials said they’re ordering a rotation of prison guards around the state of Tamaulipas to help ensure order and security.

Two months ago, another tunnel was discovered. It was 45 feet long and 16 feet deep. Authorities used a geothermal device to find it.