Brasilia: Brazil’s army announced on Thursday that it nabbed more than 2,000 knives, hundreds of cellphones, drugs, cash and alcohol during sweeps of prisons, including those involved in deadly violence earlier this year.

Troops were sent to comb 10 prisons in the wake of the bloodletting in which 140 people were killed in gang violence.

“It’s an additional measure... in this tense time,” said Defense Minister Raul Jungmann in a statement.

The 4,000 soldiers were sent to prisons in the Amazonian city of Manaus, where 56 prisoners died, and Rio Grande do Norte, where 26 died, among other penitentiaries.

With about 622,000 inmates in 2,766 institutions, Brazil has the world’s fourth biggest prison population and in most cases the facilities are badly overpopulated.

Conflict between rival gangs broke out late January, with some victims being beheaded in violence.