At least 75 members of a "highly dangerous" Brazilian drug cartel have dug a tunnel and escaped from Paraguayan prison in the border city of Pedro Juan Caballero.
The prisoners, who are members of the First Capital Command drug cartel, allegedly spent weeks digging the tunnel from a prison bathroom.
Elena Andrada, a police spokeswoman, said that there was only 25 metres between the tunnel and the closest guard post.
"By now they've probably crossed over to the other side," Paraguay's justice minister, Cecilia Pérez, said. "This is very serious."
"It's an operation that took days, and it is impossible that the officials did not realise that they were leaving … obviously this was a paid plan."
The prison's chief warden has been fired and five other prison guards have been suspended.
The president of the National Mechanism to Prevent Torture, Dante Leguizamón, revealed in an interview that Pedro Juan Caballero prison is considered to be "the prison with the most severe corruption problems".
"Considering the fragility of the system as a whole and crowding conditions, this is not a terribly surprising situation," he added.
Andrada revealed that five vans used in the escape had been found burnt out in the Brazilian city of Ponta Pora.
The border near Pedro Juan Caballero is known to be a transit point for drug trafficking and other criminal activity by gangs.
Paraguay's interior minister, Euclides Acevedo, said the government was in a state of "maximum alert" and had their "best investigators" on the situation to recapture the prisoners.