A secret tunnel has been discovered in a Mexican prison, stashed with drugs, alcohol and sharp tools, the media reported on Monday.
Police in Tamaulipas state on Sunday night said the tunnel in Reynosa, a city close to the US border, was hidden by bricks and was up to five metres deep, reports the BBC.
It was found after authorities used geothermal technology to detect activity underground, according to local media.
They said it was unfinished and no one has escaped.
Tamaulipas police said they were conducting a search for further holes after the latest tunnel was discovered, the BBC reported.
In 2015, one of the country's biggest drug lords, Joaquin "El Chapo" Guzman, escaped via a tunnel from Altiplano prison.
He was recaptured after six months on the run and later extradited to the US.