Rio de Janeiro officials have documented three bomb threats a day on average since the 2016 Summer Olympics began.

In the past fifteen days, police have recorded a total of over 47 bomb threats, though none have led to the discovery of any explosives. Police issued training to locals on how to identify suspicious packages and when to alert authorities about a potential bomb threat.

According to the Brazilian newspaper Folha de Sao Paulo, “All were warned about the risk posed by an abandoned bag. The orientation included taxi drivers and hotel staff. Since the training, there are been 20 times the number of calls to police to report suspicious packaging.”

They also reported that “since July 24, when the Olympics security plan was put into practice… several streets have been shut down” until officials found no threat.

The Olympic Games in Rio are feared to be a prime target for terrorists to attack. Late last month, a group of ten people who all pledged their support to Islamic State were arrested around the country after attempting to buy weapons online.

Breitbart News reported in July, “Brazilian police arrested at least 10 suspects who had pledged allegiance to the Islamic State and were allegedly planning an attack on Rio de Janeiro during the Olympics.” The group called themselves Guardians of Sharia; a minor was among them.

The Olympic Games have long been a target for terrorists. In 1996, the XXVI Olympics in Atlanta, Georgia were attacked by Eric Robert Rudolph. The bombing took place at the Centennial Olympic Park. It killed one person and injured 111 others.

The 1972 Olympic Games in Munich, Germany, experienced the most infamous attack by terrorists. Palestinian terrorists kidnapped and killed eleven Israeli Olympic team members. In addition to murdering the Israeli athletes, Palestinian outfit Black September killed a German police officer in the battle that ended the standoff.