ASUNCION (Reuters) - At least 75 inmates, including members of Brazil’s most powerful gang, escaped from a Paraguayan prison on Sunday after digging a tunnel in an operation that prison officials were believed to have been aware of, Paraguay’s government said.

The director of the penitentiary in the city of Pedro Juan Caballero, near the Brazilian border, was fired along with six other prison officials, Paraguayan Justice Minister Cecilia Perez told reporters.

The escaped prisoners included gang members from First Capital Command (PCC), Brazil’s most powerful and sophisticated organized crime group, the government said.

“It’s an operation that took days and it is impossible that the officials did not realize that they were leaving ... obviously this was a paid plan,” Perez told local radio station Monumental.

The border region near Pedro Juan Caballero is considered a transit point for drug trafficking and other criminal activity by gangs like Brazil’s PCC and Comando Vermelho, or Red Command.

The government said it alerted Brazil’s federal police, but the prisoners are believed to still be in Paraguayan territory.

“In that area, there are many woods and they know the territory ... these are highly dangerous people,” Paraguayan Attorney General Sandra Quinonez told Monumental.

The government of the neighboring Brazilian state of Mato Grosso do Sul said it had increased security along the border.

Brazilian Justice Minister Sergio Moro said he was ready to help Paraguay recapture the escaped criminals and was working with border-state authorities to stop them re-entering Brazil.

“If they return to Brazil, they will get a one-way ticket to a federal penitentiary,” Moro said in a Twitter message.