Brazilian Military Police backed by Marine troops occupied the massive Maré favela next to Rio de Janeiro's Galeao international airport on March 31, allegedly without firing a shot. The aim was to secure one of the city's most violent districts, long under control of drug gangs, ahead of the World Cup, to be held in Brazil in June. Shock troops of the elite Special Police Operations Battalion (BOPE) and Marines in armored vehicles and helicopters secured the Maré area, where 130,000 people live in poverty on the north side of Rio. Police said they seized guns and 450 kilos of marijuana, and arrested two suspected dealers. But residents said most gang leaders slipped out the favela ahead of the occupation. The operation had been expected; in preceding days Police Pacification Units (UPPs) had been installed in 174 of Rio's favelas -- home to around 600,000 people.