RIO DE JANEIRO -- Mayor Eduardo Paes expressed confidence Saturday in security for next year's Rio de Janeiro Olympics, but was also cautious in the wake of the attacks in Paris just over a week ago.

"We have to worry," Paes said, speaking at the field hockey venue for the games. "The attacks to Paris were not to Paris, but to the civilized world. ... This can happen anywhere and we are going to take good care of the security of the Olympic Games, and things are going to go well."

Brazilian government officials have said that 85,000 soldiers, police and security agents will be deployed for the Rio games, which is reported to be twice as many as the 2012 London Olympics.

Jose Mariano Beltrame, the top security official for Rio de Janeiro state, said earlier in the week that security plans have not changed because of the Paris attacks.

Brazil has little experience with attacks like those in Paris. The major problem in Rio is street crime, robberies and assaults -- part of the endemic violence in a city rife with guns.

Much of the violence takes place in sprawling hillside slums where police are outnumbered by armed gangs. Some of these areas border Rio's famous beach areas in the south of the city, which will host several Olympic events.

Brazil is larger than the continental United States and has thousands of miles (kilometres) of porous borders, some slicing through the Amazon jungle region.