A small war took place last week in Rio de Janeiro, Brazil, between Brazilian forces and hundreds of drug traffickers holed up in the shantytown complex dubbed Complexo do AlemÃ£o. After recent efforts by officials to pacify Rio's drug and gang-related violence ahead of the upcoming the 2014 World Cup and the 2016 Olympics Games, drug gangs struck out last week - attacking police stations and staging mass robberies. After days of preparation, Brazilian security forces launched a raid in the Complexo do AlemÃ£o, where between 500 and 600 drug traffickers were holed up. At least 42 people were killed in the violence last week, with security forces taking control of many neighborhoods. A relatively low number of arrests were made, and authorities warn of further conflict as continue to flush out more suspects in Rio's maze of favelas. ( 40 photos total