London’s Heathrow Airport, Europe’s busiest air hub, suspended flight departures for about an hour Tuesday after a reported drone sighting – just three weeks after a spate of drone sightings shut the city’s Gatwick Airport.

The suspension of takeoffs from Heathrow was announced shortly before 6 p.m. local time Tuesday. The outgoing flights resumed about an hour later.

London’s Metropolitan Police said it received a report about a drone “in the vicinity” of the airport.

“We are responding to a drone sighting at Heathrow,” the airport said. “As a precautionary measure, we have stopped departures while we investigate.”

The flight tracking site FlightRadar showed planes were still able to land at the airport after the announcement.

The incident comes after the pre-Christmas disruption at Gatwick Airport over three days because of drone sightings. More than 1,000 flights were canceled or diverted, affecting 140,000 travelers at Britain’s second-biggest hub.

Gatwick has since said it has invested in military-grade anti-drone technology, while Heathrow said that it also would do so.

In response to the chaos at Gatwick, Transport Secretary Chris Grayling told lawmakers on Monday that drone exclusion zones around British airports were being extended and that operators will have to register their devices.

Authorities also will be allowed to fine users up to $128 for failing to comply when instructed to land a drone, or not showing registration to operate one.

The half-mile exclusion zone around airports will be extended to three miles.

Grayling said the disruption at Gatwick between Dec. 19 and 21 was “deliberate, irresponsible and calculated, as well as illegal.”

Two people were arrested for suspected “criminal use of drones’” in the Gatwick case.

Heathrow served 78 million passengers in 2017, with 81 airlines flying to 204 destinations in 85 countries around the world. Its most popular destination is the Big Apple.

With Post wires