Thirteen inmates were killed and two others injured on Monday in yet another bloody fight in a notorious Ecuadorian prison, law enforcement officials said.
"Unfortunately, central command reports 13 (inmates) dead and two injured," the South American country's prison authority SNAI said on Twitter.
The incident took place at the same Bellavista prison in the town of Santo Domingo de los Colorados, about 80 kilometres (50 miles) from Quito, where 44 inmates were killed in a bloody brawl in May.
Prison officials, aided by the military and the police, were able to regain control of the facility, SNAI said.
Interior Minister Patricio Carrillo later told a press conference that current information indicated "most" of the victims were Venezuelan.
Local media reported that some prisoners were decapitated or dismembered during the fight.
"Relatives of the inmates waited anxiously outside the prison, as images of dismembered bodies reached their cell phones and they remained undaunted by the entry of ambulances," read a story in the national newspaper El Universo.
Carrillo said that the "primitive act of barbarism" indicated the "psychological profile" of the inmates who took part in the brawl.
"So far, 13 bodies have been recovered and a total inspection is being carried out inside the prison," he said, adding it was "quite probable" more bodies would be found.
Some 220 inmates escaped from the prison during the May riot, but most of them have been recaptured.
Vicious prison riots are common in prisons in Ecuador, where drug gangs are vying for control of trafficking routes.
Those rivalries sometimes explode into grisly violence behind bars, with some inmates hacked to death or beheaded with machetes.
Nestled between the world's biggest cocaine producers, Colombia and Peru, Ecuador has seen a surge of violence blamed on fighting between rival drug groups.
The country of 17.7 million people is popular with traffickers because of its porous borders, dollarized economy and major seaports for export.
Prisons are overcrowded and short on guards, and rampant corruption means inmates can lay their hands on all sorts of contraband, including firearms and explosives.
Since February 2021, there have been nearly a dozen prison massacres in the country, some of which have become among the worst in Latin America, with some 400 inmates killed.