Elite police commando units fanned out on streets of southern Brazil Saturday, in an effort to contain a wave of violent attacks over the past two weeks, authorities said.
The attacks -- allegedly ordered by criminal gangs from within Brazil's prisons -- have seen buses and private passenger cars torched and police fired upon in some 30 cities in the state of Santa Catarina since January 30.
"With the support of the National Police Force, we have launched Operation Secure Santa Catarina, Joao Carlos Neves, spokesman for the state's military police force.
Reinforcements began arriving on Friday from elite federal police units to help contain the violence that has overrun the region.
Authorities said the police already have made scores of arrests, and said prison officials also have transferred some inmates believed responsible for the mayhem to other facilities.
The prison-based crime rings reportedly unleashed the crime wave to pressure authorities to provide better living conditions for inmates.
Press reports have blamed a gang called the First Group of the Capital, similar to a Sao Paulo-based prison syndicate known as the PCC, or First Command of the Capital.
The PCC was allegedly involved in various attacks and clashes with police that claimed more than 300 lives in and around Sao Paulo between October and early December.
Santa Catarina, a state with some 6.2 million inhabitants, also witnessed an outbreak of criminal violence in November.
Much of the violence has been carried out in the city of Florianopolis, capital of the southern state.