Munich airport in Germany has reopened after a scare in the form of several drone sightings forced it to close and cancel more than a dozen flights on the night of October 2. 

BBC News reports that at least 17 flights were grounded in Munich, affecting nearly 3,000 passengers and associated cargo capacity, and air authorities diverted a further 15 flights to nearby cities. 

On October 3, a spokesperson for German flag carrier Lufthansa said, "flight operations have since resumed according to schedule."

Because it was dark, no information on the type, size or origins of the drones was confirmed, Federal Police spokesperson Stefan Bayer told the Bild Newspaper. police said the drones were first seen at 21:30 local time, and then again an hour later. 

Meanwhile Belgian media reports that authorities in Belgium are investigating sightings of 15 drones, which were seen above the Elsenborn military site near the German border. 

In separate recent incidents, 20 Russian drones crossed into Poland and Russian MiG-31 jets entered Estonian airspace, the BBC said.

Recent drone sightings across the European Union have prompted a leaders' summit in Copenhagen this week. On October 1, at the summit, Danish Prime Minister Mette Frederiksen warned that Europe is in the middle of a hybrid war waged by Russia and the continent must arm itself, according to AP News.