At least 40 inmates in Brazil have been strangled to death in separate jails - a day after a fight between rival prison gangs killed 15 people.

The latest violence took place across four prisons in the Amazon jungle city of Manaus, and those who died were discovered by staff during routine inspections.

Local officials said all of the prisoners showed signs of asphyxia.

Image: Brazilian riot police prepare to invade the Puraquequara Prison facility in Manaus, Amazonas

A federal task force is being sent to Manaus in an effort to halt the violence.

Prison clashes are known to spread rapidly in Brazil, where drug gangs have de facto control over most jails.


In January 2017, nearly 150 inmates died at the hands of other prisoners during several weeks of fighting among rival crime gang members at prisons in northern states.

Many of those victims had their heads cut off or their hearts and intestines ripped out.

Image: Family members of inmates pray in front of the Puraquequara Prison facility

On Sunday, 15 inmates were killed during a riot at Manaus' Anisio Jobim Prison Complex, where 56 prisoners died in the violence two years earlier.

The prisoners had begun fighting one another before midday on Sunday and security reinforcements were rushed in and managed to regain control within 45 minutes, local authorities said.

Amazonas state governor Wilson Lima said reinforcements were being sent to "help us in this moment of crisis and a problem that is national: the problem of prisons".

Image: Relatives of inmates react to the news of the deaths

Brazil's far-right president Jair Bolsonaro has vowed to regain control of the country's prisons as well as building additional ones.

However, the vast majority of jails are administered at state level and have been overcrowded and out of control for decades.

Several drug-trafficking and other criminal gangs in Brazil run much of their day-to-day business from prisons.

The 2017 deaths were largely gang-related, which prompted authorities to increase efforts to separate factions and frequently transfer prisoners.