American planes over Zagreb; Police helicopters are also on alert

As stated, at that time, airplanes will be visible on the outskirts of the Croatian capital.

In the statement of the U.S. Embassy, reported by the Croatian portal 24sata, it is stated that the training will be carried out after several months of careful preparations in coordination with the Croatian authorities.

"The exercise itself will take place in several locations in and around the US Embassy," the announcement states, adding that during the exercise, airplanes will be seen on the outskirts of Zagreb. This exercise, they say, is the culmination of a long-standing joint combined training (JCET) program between the US Special Operations Command in Europe and the Croatian police.

"This latest exercise demonstrates the commitment that the United States shares in increasing counterterrorism and first response capabilities with Croatia, a key NATO ally," the portal reports.

U.S. embassies and consulates around the world are required to conduct annual crisis management exercises to prepare employees for natural or man-made emergencies, the statement said.

"Strong bilateral relations and cooperation between the United States and the Government of Croatia create a unique opportunity to conduct this joint, large-scale crisis management exercise live," reports the portal.

The US Embassy says it understands that this exercise will affect normal operations at the Embassy and the surrounding area and appreciates the support of those who, they say, were affected by the exercise.

It is also reported on social networks that the citizens of Zagreb have been warned that police helicopters will be flying over the city.