Arrivals and departures to Pittsburgh International Airport were briefly halted Monday after reports of an unauthorized drone flying on the north side of the airfield.

The US Federal Aviation Administration lifted the restrictions about 1 p.m. local time, roughly an hour and 20 minutes after they were imposed, according to an air-traffic bulletin and an agency statement. 

Operating even small drones near commercial airports is prohibited without approval from FAA controllers because of the risks of a midair collision. Local police were attempting to locate the operator of the device, the FAA said. 

While rare, drone sightings near airports have caused major concerns and led to severe flight disruptions. In 2018, drone activity created dayslong halts to flights at London’s Gatwick Airport. Dozens of flights were delayed at Newark Liberty International Airport in 2019 after an apparent near-collision between and airliner and a drone.