Brazilian marines and paramilitary police stormed one of Rio\'s most notorious shantytowns, as the city cleans up ahead of the 2014 World Cup and the 2016 Olympic Games. It took just 20 minutes for the security forces to take over the Manguinhos slum in the pre-dawn raid involving hundreds of police assisted by helicopters hovering overhead, and armored personnel carriers carrying 170 marines that plowed through road obstacles set up in the narrow streets. No shots were fired, but three people were arrested. Police said that five alleged drug crime bosses that had fled to a nearby favela were killed on Saturday. Police also increased their presence in Jacarezinho, a nearby favela and a major crack cocaine consumption center. Some 1,300 heavily armed police participated in the operations, officials said. The two favelas, home to some 70,000 people, are located 10 kilometers (six miles) from downtown Rio and are strongholds of the powerful Comando Vermelho (CV) drug gang. The operation is \"another step toward peace, for reducing the number of homicides, car theft, and home break-ins,\" said Rio de Janeiro state Governor Sergio Cabral. \"The practical effect of this is measured by a more peaceful life for citizens,\" Cabral said. Around midday, the police raised the Brazilian flag in the Manguinhos town square and sang the national anthem, symbolically freeing the shantytown from the crime bosses. What follows now is \"a meticulous search for drugs, weapons and the arrest of criminals,\" said Rio military police spokesman Federico Caldas. Paramilitary police will keep the peace until a unit with agents especially trained to handle favela affairs arrives in December, Caldas said. Hundreds of police officers blocked entrances to Jacarezinho, but did not occupy the site. \"The military police needs more time to occupy this area. What we will do is to have a constant presence there,\" deputy civil police chief Fernando Veloso told TV Globo News.