Overview

• Air traffic control closed both runways around 10:30 p.m. after police-confirmed sightings above the airfield and earlier reports nearby.
• Seventeen departures were canceled and 15 arrivals diverted, leaving roughly 3,000 travelers stranded overnight with field beds set up in terminals.
• State and federal police, including a helicopter, searched the area but found no devices or operators.
• Investigators have not determined how many drones were involved or what type they were as operations resumed Friday morning.
• The incident fits a wider pattern of unexplained overflights in northern Germany, Denmark and Norway that has spurred officials to pursue stronger detection systems, legal reforms and a national drone-defense center.