More than 100 inmates have escaped from a jail in Mexico after fleeing through a tunnel dug in an old carpentry workshop.
The escape of 132 prisoners from the city of Piedras Negras near the Texas town of Eagle Pass has led to a huge manhunt with federal police and the Mexican army deployed on roads and motorways around the area and the US Border Patrol also taking part.
The prison's director, security chief and shift guard have been questioned over the matter and authorities have asked a judge to issue a detention order against the three, said the office of state attorney general Homero Ramos Gloria.
The Coahuila state attorney general also said that, while the escape took place at 2.15pm local time, it took an hour or so for guards to notice.
After emerging from the tunnel, the inmates "cut a wire fence from where, according to prison authorities, the convicts got out one by one and reached a vacant lot," a statement revealed.
Evidence of the escape gathered so far includes fragments of a BlackBerry phone, pieces of a sim card, a pair of flip-flops, two other flip-flops, three long pieces of rope, an electric wire and a broken padlock.
Rewards of £9,600 for information leading to the capture of each inmate are being offered.
Local authorities said a special police unit killed four suspects in a clash in the town of Castanos four hours after the Piedras Negras escape was reported, and that there are indications that the dead were inmates.
Several mass prison breaks have taken place in Mexico since 2010, with the biggest to date taking place in December of that year, when 141 inmates escaped from the Nuevo Laredo prison in the northeastern state of Tamaulipas.