At least 75 inmates died in three jails in Ecuador, one of the deadliest fighting recorded in years.
Authorities deployed military and riot police to quell the violence that started on Tuesday.
Officials suspect the fights were prompted by a battle for control of the jails after a gang leader was killed in December.
The three jails hold 70% of the country’s prisoners, according to the head of the Ecuadorian prison system.
Edmundo Moncayo said 33 prisoners had been killed in a jail in Cuenca, 21 in Guayaquil and 8 in Latacunga by Tuesday evening. He came out again later and added 13 more without specifying in which jails they had occurred.
There are reports of a number of police officers injured but all of those killed are thought to be inmates.
Mr Moncayo said tension had been running high in the prisons since the killing in December of Jorge Luis Zambrano, alias Itch.
Zambrano, the leader of the Choneros gang, was shot dead in a cafeteria just months after being released from jail.
During his time in prison, he and his gang ran a lucrative smuggling, drug dealing and extortion ring mainly inside these prisons.
Tuesday’s deadly fights are thought to have been over who should replace Zambrano and were said to have been planned and highly organised, according to Interior Minister Patricio Pazmiño.
Over the past two years, the government has twice declared emergency measures in Ecuador’s jails – in May 2019 when 10 inmates were killed within weeks and in August 2020 when a key witness in a corruption case was murdered inside his cell.