Croatian Authorities has opened a probe: As they witnessed a military drone’s crash site. Apparently, it flew all the way from the Ukrainian war zone and crashed on the outskirts of the Croatian capital, Zagreb, triggering a loud blast but causing no casualties.

The Croatian police said they arrived at the scene of the explosion on the outskirts of Zagreb after calls from residents. They said they found a large crater and two parachutes in a wooded area. Some parked cars were damaged.

A statement issued on Friday after Croatia’s National Security Council meeting said the “pilotless military aircraft” entered Croatian airspace overnight from neighboring Hungary at a speed of 700 kilometers per hour (430mph) and an altitude of 1,300 meters (4,300 feet).

Zagreb Mayor Tomislav Tomasevic said parts of the flying object were scattered in several locations. He said authorities were working to determine how the incident happened and that initial findings indicated it was an accident.

“No one was hurt and that is good fortune,” said Tomasevic. “It is a relatively big object. … It is amazing that no one was hurt.”