MUNICH – Munich Airport in Germany was forced to close temporarily last night after a wave of drone sightings, the latest European aviation hub to shutter over unexplained drone flights.

A total of 17 flights were grounded shortly after 10 p.m. local time on Thursday, affecting nearly 3,000 passengers, the airport said in a statement.

In addition, 15 arriving flights were diverted to the German cities of Stuttgart, Nuremberg and Frankfurt, as well as Vienna in neighboring Austria, the statement said.

A call handler fielding passenger enquiries for Munich Airport overnight told CNN: “Some flights are still waiting to take off, others have been canceled. Everything is under control and the airport is due to reopen at 5 a.m.”

The airport in Bavaria, southern Germany, is a hub for German flag-carrier Lufthansa, and served nearly 20 million passengers in the first half of this year.

It becomes the latest European airport to close after sightings of drones nearby. A spate of sightings over several airports in Denmark last week saw tens of thousands of passengers impacted.

Denmark later banned all civil drone flights in its airspace as it prepared to host a summit of European leaders in Copenhagen this week to discuss support for Ukraine in its fight against Russia, and bolstering European security.

Europe has been on high alert in recent weeks due to a string of drone sightings, as well as alleged incursions by Russian drones into NATO airspace over Poland and Romania, and the alleged violation of Estonian airspace by Russian fighter jets.

Danish Prime Minister Mette Frederiksen said that while authorities cannot conclude who was behind the drone sightings in Denmark, “we can at least conclude that there is primarily one country that poses a threat to Europe’s security – and that is Russia.”

The Kremlin has denied involvement in the drone sightings, as well as that it violated Estonian airspace.

Munich, a historic city of more than 1 million people, was already on edge after its famed Oktoberfest beer festival was closed for several hours earlier this week due to a bomb threat. – CNN