BELGRADE – Europe is not the place to be for American tourists this summer, according to the State Department. A travel advisory warns US citizens there is a risk of terrorist attacks on tourist sites and major events in the Old World until the end of August.

Though no specific threat was named, many European countries have already suffered attacks connected to the so-called Islamic State (IS, formerly ISIS/ISIL). In Belgium, 32 people were killed and 340 injured in the March 22 bombings at the airport in Zaventem and a downtown Brussels metro station.

France is still under the state of emergency declared last November, when terrorists killed 130 and injured 368 in a series of attacks in Paris.

In the advisory issued Tuesday morning, the State Department alerted US citizens “to the risk of potential terrorist attacks throughout Europe, targeting major events, tourist sites, restaurants, commercial centers and transportation.”

“The large number of tourists visiting Europe in the summer months will present greater targets for terrorists planning attacks in public locations, especially at large events,” the warning said.

France and Poland were singled out in the advisory, due to events drawing large crowds of people. The State Department specifically named the July 2-24 Tour de France cycling race, and the European soccer championships, scheduled from June 10 to July 10 at venues across France.

Poland is imposing additional border controls and security measures between July 4 and August 2. The Eastern European country is expecting up to 2.5 million people in Krakow for the Roman Catholic Church’s World Youth Day events, scheduled for July 26-31.

US citizens should be aware that the “local infrastructure may be strained due to the large number of visitors,” the State Department said.

Americans were also urged to avoid crowds, “exercise vigilance when in public places or using mass transportation,” and be prepared for additional security measures and “unexpected disruptions.”

The travel advisory expires on August 31.