The Confederations Cup soccer tournament gets underway this weekend in Brazil, and authorities have brought in drones, thermal cameras and thousands of troops to patrol the six stadiums to bolster security in an often violent country.

But experts say visitors will be immediately vulnerable once they venture away from secured areas. They may run even a greater risk than usual, with many police being taken from their regular street duties to patrol areas around the stadiums.

As host for this event, as well as a papal visit in July, next year's World Cup and the 2016 Olympics, Brazil's government has pledged to curb crime and violence. But the country still has an alarmingly high murder rate, and armed thefts and carjackings continue to be facts of daily life.