Police officers (top R) patrol the Parque Alegria slum as a military helicopter flies overhead during an operation to install the Police Peacekeeping Unit (UPP) in the region, in Rio de Janeiro March 3, 2013. The introduction of the peacekeeping program in the region is part of efforts to crack down on crime and increase security as the city prepares to host the 2014 World Cup soccer tournament and the 2016 Olympic Games. REUTERS/Ricardo Moraes (BRAZIL - Tags: CRIME LAW CIVIL UNREST SPORT SOCCER WORLD CUP)