At least 40 inmates have been found dead at separate prisons in northern Brazil a day after 15 prisoners were killed in gang clashes, officials say.
The latest deaths, which were reported in Manaus, the capital of Amazonas state, all appeared to be the result of asphyxiation, authorities said.
They added that staff had discovered the victims during routine inspections at four different prison facilities.
A task force has been sent to “control the disturbances,” officials said.
Several other inmates were injured in Monday’s incidents, according to Brazil’s Globo news website (in Portuguese).
The majority of the victims were discovered at the Antônio Trindade institute near Manaus, while deaths were also reported at the Puraquequara and Provisional Detention Center facilities in Amazonas state.
The local governor, Wilson Lima, described the situation on Monday as a “crisis”.
He added that an investigation launched on Sunday would be extended to include the latest deaths.
On Sunday, clashes reportedly broke out during visiting hours at Anísio Jobim Penitentiary Complex in the region.
Officials said the prisoners were stabbed with sharpened toothbrushes and strangled to death.
An investigation is reportedly under way to determine the cause of the violence over the weekend, which was witnessed by visitors.
“It was total chaos,” the mother of an inmate – who did not wish to be named – told the Rio Times.
“Everyone started to run, and everyone was pounding on the cell gates, at the doors, and running down the corridors.”
It comes only two years after infighting killed 56 at the same jail, one of the deadliest riots ever in a Brazilian prison.
Brazil has the world’s third-largest prison population – 712,305 inmates in April this year, according to official figures.
