The latest uprising reportedly took place early on Friday at the Monte Cristo prison facility near Boa Vista. The penitentiary is the largest in the Brazilian state of Roraima. According to authorities, security officials had gained control over the situation.

A local government spokeswoman told AFP news agency that the violence did not appear to be an all-out riot, but rather a fast, early-morning attack by one group of inmates against another.

Most of the killings were carried out with knives, she said, with no firearms having so far been found in the prison.

In October, 10 inmates were killed at the same prison during clashes between rival drug gangs.

Second prison uprising in a week

Experts had predicted more violence in Brazil's prison system in the wake of a massacre over the weekend, which saw members of one drug gang butcher inmates from a rival criminal group.

At least 56 people died on Sunday after a riot broke out at the Anisio Jobim Penitentiary Complex in Manaus, a city in the northern state of Amazonas - making it the second deadliest in the country's history.

In 1992, 111 prisoners were killed during a riot in a Sao Paulo prison - most of them by police when they stormed the jail.

Prison crisis in Brazil

Brazilian President Michel Temer is facing heavy criticism for overpopulated prisons, many of which are de facto run by drug gangs in brutal fashion. Temer said Thursday the federal government would spend $250 million (237 million euros) to build at least one prison in each state in Brazil, but rights activists question whether this move is the right answer.

"This is a national crisis," said Uziel Castro, security secretary of Roraima.

ksb,kbd/kms, se (AFP, Reuters)