Since Rio de Janeiro was awarded the 2016 Summer Olympics, the city's crime problems have received more attention. Rio's mayor has admitted that there are "big issues" facing the city in securing the Games from violence. However, he also said that such concerns and issues were presented to the IOC throughout the bidding process. The governor of the state of Rio de Janeiro also highlighted the fact that London faced security problems, with a terrorist attack occurring there on the day after the IOC chose London to host the 2012 Summer Olympics. The estimate was that 5,000 men of the National Public Security Force and 22,000 military officers (14,800 Army; 5,900 Navy and 1,300 of the Brazilian Air Force), in addition to the fixed quota of Rio de Janeiro, will act during the Olympic Games. Many of these officers have been training for possible terrorist attacks, such as on the Metrô. To ensure that no unauthorized persons would be able to enter the Games, additional screening measures were enacted at venues.