It's been an alarming past few weeks for fans of international travel.

In March, a Swiss woman was gang-raped while she was camped out in a forest with her husband after a day of biking around the central Indian state of Madhya Pradesh. And on Monday, an American tourist was raped by three men over the course of six hours while aboard a public van near the seaside resort town of Copacabana .

The incidents have already taken their public-relations toll. The Brazil rape is the latest evidence that the country has a growing sexual assault problem -- reports of rapes there have risen 150 percent since 2009 -- and raises questions about Brazil's readiness for the 2014 World Cup and 2016 Olympic Games.

And in a new survey of 1,200 tour operations across India, the Associated Chambers of Commerce and Industry of India found that the number of inbound tourists to the country has dropped 25 percent since December, while the influx of female travelers is down 35 percent.

That's not surprising, since research shows that violence and other upheaval tends to scare away tourists.

So, which countries should foreign travelers avoid, or at least be especially careful in?

Statistics for attacks on tourists are hard to come by, but one way to look at travel risks is through the travel warnings that governments issue for their citizens. Here's a map put together by the CBC, based on warnings from Canada's Department of Foreign Affairs (click here for the interactive version):