Despite the deployment this week of 1,200 soldiers to replace striking police, the streets of southeastern Espirito Santo state -- particularly its capital Vitoria -- remained lethal.
The troops sent so far "are not sufficient," state acting governor Cesar Colnago said.
Brazilian media broadcast footage of looting, carjackings and muggings in municipalities abandoned by police officers, who are seeking better pay.
According to the local police union, there have been 90 murders since the unrest started Saturday, compared to just four in all of January.
There have been 200 robberies and about 90 million reais ($29 million) in damage to businesses, including from mass looting of stores, the union said. The government has yet to give official crime statistics.
Colnago said the elite National Force and the military, which has sent soldiers with rifles to try to restore calm, would step up their presence.
"We are taking steps to increase the level of the National Force, which is police, and of the armed forces so that we can have security," he told journalists, adding that people were so fearful of being attacked on the streets that it was as if they were in prison.
Brazilian law bars the Military Police -- as the force patrolling cities throughout Latin America's biggest country is known -- from going on strike.
In Espirito Santo, however, relatives and sympathizers are blockading police stations, and officers inside are making no effort to come out -- effectively leaving the city unguarded.
The police want better conditions and higher salaries. A court declared the action an illegal strike and the state police chief has been replaced.
The crisis reflects nationwide budget crises in Brazil, which has faced a crippling recession for two years and is struggling to return to growth.
The country is also one of the most violent in the world, with heavily armed criminals battling both on the streets and in prisons. Last month clashes inside a prison near the northern city of Natal left 26 people dead, prompting the deployment of army troops.
Soldiers were also deployed to Rio de Janeiro during legislative elections last October, as they had been in large numbers during the Olympics two months earlier.
There were jitters in the Olympic city Wednesday when a statement was published on Facebook purporting to announce that Rio police would stage a copycat strike starting Friday, with family members blockading stations.
However, police authorities called the statement, which was made to look official, a fake.