The military-run police announced they had ordered 1200 officers off of desk work and into the streets to quell a series of attacks that have renewed concerns about security for the 2014 World Cup and 2016 Olympics.
Rio has been hit by a spike in violence since Sunday, with at least five mass robberies of motorists on key highways, including the one leading to the international airport.
Witnesses say the armed men have used cars to block roadways in broad daylight, then moved down the line of trapped vehicles, yanking people from their cars and robbing them. At least two people who resisted were shot to death in a poor area of northern Rio, police said.
Suspected drug gang members, armed with assault rifles, pistols and even grenades, have tossed molotov cocktails into several of the cars after motorists fled.
Burned-out husks of the cars littering the sides of roads in several parts of the city, including wealthier areas that are spared to the rampant violence that permeates the city's slums.
Police responded by deploying riot officers on expressways into the city of 6 million people and sending patrols into 15 gang-controlled shantytowns to hunt down the gang members they hold responsible for the attacks.
Police said one armed man died in a confrontation with officers on Tuesday.
Rio state Public Safety Director Jose Beltrame, in charge of the security forces, said the attackers are trying to disrupt a city campaign to push gangs out of key shantytowns. Officials say 13 shantytowns have been pacified over the past two years and they aim to free 40 of gang control by the time of soccer's World Cup, a small proportion of Rio's more than 1,000 slums.
The national minister of justice, Luiz Paulo Barreto, assured executives of soccer's governing body, FIFA, on Tuesday that the country is preparing to welcome the games in a climate of "peace and tranquility."
Barreto specified that Rio and the 11 other cities which will host World Cup matches will have command centres from which various Brazilian and foreign law enforcement organisations can work in unison.
