Updated

Police in Brazil have entered two prisons in the country's northern state of Rio Grande do Norte where a riot left at least 10 inmates dead on Saturday, authorities said Sunday.

A statement released by the office in charge of state penitentiaries said the rebellion started Saturday afternoon in the Alcacuz and Rogerio Coutinho detention facilities, located next to each other outside the city of Natal.

Police entered the prisons on Sunday morning, according to the statement.

The riot erupted from fighting between rival gangs and was the latest in a series of massacres in the South America country's penitentiaries that have killed more than 100.

Authorities have said they expect the death toll from Saturday's rebellion to rise.

The Alcacuz facility has capacity for 620 inmates, but houses 1,083.

The last rebellion in Alcacuz prison was in November 2015, when a tunnel was discovered in one pavilion. The facility should house 620 inmates but has 1,083.

The recent outbreak of prison violence in Brazil began on Jan. 1-2, when 56 inmates were killed in the northern state of Amazonas. Authorities said the Family of the North gang targeted members of Brazil's most powerful criminal gang, First Command, in a clash over control of drug-trafficking routes in northern states. Many of the dead were beheaded and dismembered.

Then on Jan. 6, in the neighboring state of Roraima, 33 prisoners were killed, many with their hearts and intestines ripped out.

Experts say First Command, known by the Portuguese acronym PCC, is exploiting overcrowding and squalid conditions in the Brazil's penitentiaries to expand its reach across the national prison system. The gang runs drug-trafficking operations both inside and outside prisons even though many of its leaders are in maximum security penitentiaries in Sao Paulo state.