Wary that the international sporting event is a potential prime target for terrorists, Brazilian forces have been working with specialist French SWAT teams to simulate attack scenarios.
In one drill, Brazil special forces and a police dog chase down an armed gunman to thwart a possible attack on Rio's subway system. The dramatic display is meant to reassure journalists that a country with limited experience in handling terrorism is ready for the unthinkable.
"There is not a specific threat," said Lt. Gen. Luiz Linhares with the Brazilian Ministry of Defense. "You have to screen for a great (spectrum) of threat."
The Brazilian government
said it is not taking any chances -- especially after the recent terror attacks around the world, including in Turkey
and Saudi Arabia
Linhares said authorities will be screening the ticket names of the hundreds of thousands coming for the Rio Olympics, South America's first games.
Brazil's intelligence agency reported in April that the number of those influenced by ISIS ideology had increased in recent months but insisted there was no threat to the Olympics.
Brazil mostly lacks the presence of extremist networks that terrorists rely upon, but at least one ISIS fighter tweeted after the November 2015 Paris attacks that Brazil would be next. Several ISIS members have launched a Telegram channel in Portuguese, the official language of Brazil.
The UK government's latest travel warning advises citizens
going to Brazil that "there is an underlying threat from terrorism. Attacks, although unlikely, could be indiscriminate, including in places frequented by foreigners."
There have been no major terror attacks in Brazil in recent years, but Peter Martin, CEO of security firm AFIMAC Global, said the country does have serious organized crime issues and therefore could leverage high-level training to combat that problem within the Brazilian special forces.
"When you're going after gangs like that, there are a lot of similarities to terrorists with intercepted communications, informants trying to penetrate the organization, trying to understand what the next target is," Martin said.
"It is different, but a lot of the methodologies apply. Brazil has been doing that for a long time."
Problems with police
Some 22,000 troops will be stationed at the games, officials said, but the capability of the police force has been the focus of recent scrutiny.
For days, members of Rio's law enforcement have been protesting over late wages. The state of Rio de Janeiro requested an emergency federal bailout after it said it was unable to fund essential public services.
Angry police officers have been camping out
at the international arrivals hall of Rio de Janeiro's main airport holding up banners that say, "Welcome to hell," and warning visitors they will not be safe in the country.
A 2.9 billion-real bailout (roughly $850 million) was made available last week after acting Gov. Francisco Dornelles said the games could be a "big failure" without the funds. It's believed that the back pay will be distributed this week.
Rio de Janeiro Mayor Eduardo Paes told CNN
this week the state was doing a "terrible" job in regard to security in the lead-up to the games.
"It's completely failing at its work of policing and taking care of people," Paes said.
But Brazilian officials later put on a united front to assure the world that Rio was up to the task of hosting sport's greatest showpiece.
Delays in construction
Also complicating security efforts is the unfinished construction of several Olympics sites and infrastructure.
"The construction is so far behind. (There are) the roads that were meant to have been built by now, and we're not sure if they're going to be open in time," Martin said.
A tremendous amount of planning goes into mapping out the fastest routes to secure medical attention or safe zones. Parking for events may end up being farther away, he said, which means exposing people to being outside the security perimeter for longer periods of time.
"Because of the lack of development, we're still not being told where all of those are going to be right now. Usually by now, we'd have that planned and done."
What to do if you're going to Rio
Martin said anyone traveling to Rio for the Olympics should know how to reach emergency services and monitor the situation on an ongoing basis.
"People need to understand that these situations are fluid, and it's not enough to make an assessment a month out and say, 'I'm good to go.' You want to monitor the situation quite frequently," he said.
"Understand that the police response is going to be limited potentially if they go on strike. Know your local hospitals, know how to dial (numbers). Take more personal responsibility to your safety."