Munich Airport reopened on Friday after drone sightings forced its closure Thursday night, grounding at least 17 flights and diverting 15 more, affecting nearly 3,000 passengers.

Departing flights were suspended, and arriving flights were redirected to nearby airports including Stuttgart, Nuremberg, Vienna, and Frankfurt.

Authorities could not immediately determine the drones’ origin, type, or size, and Federal Police said the sightings occurred after dark.

The incident comes amid a series of recent drone disruptions at European airports, which have raised security concerns and prompted a leaders’ summit in Copenhagen, the BBC has reported.

Munich authorities accommodated stranded passengers overnight with blankets, snacks, and camp beds, while the city continues to host the annual Oktoberfest festival, which had already faced a half-day closure earlier in the week due to a bomb scare.