At least one police officer and nine inmates were killed during a massive operation at Tacumbú prison, Paraguay’s largest, officials said.

Authorities were aiming to regain control of the prison, which had largely been taken over by criminal gangs.

“Unfortunately, we have to report that we have one casualty within the police ranks”, - said National Police Commander Carlos Benítez. He added that 9 inmates were killed during the operation, which involved thousands of police and military personnel. Benítez said that around 12 of the 36 injuries reported among the police were from gunshots. 2 military personnel were lightly wounded.

Tacumbú, located in one of the capital Asuncion’s poorest districts, was the scene of a violent riot in October during which alleged Rotela Clan members set the prison ablaze and held 22 police officers hostage for over 15 hours.

Some 700 inmates at Tacumbú have been transferred to other detention centers.