Heathrow airport has halted departures on Tuesday afternoon after reports of a drone sighting.
A statement from Heathrow Airport said flights were halted “to prevent any threat to operational safety”.
It said: "We are responding to a drone sighting at Heathrow and are working closely with the Met Police to prevent any threat to operational safety.
"As a precautionary measure, we have stopped departures while we investigate.
"We apologise to passengers for any inconvenience this may cause."
In December, flights out of Gatwick airport were seriously disrupted after drone sightings.
Over 140,000 passengers were affected as around 1,000 aircrafts were cancelled or diverted.
Transport Secretary Chris Grayling had previously warned of “tough penalties” for anyone tempted to copy the Gatwick drone incident.
After the sightings at Gatwick airport, he told talkRADIO’s Julia Hartley-Brewer: “We’ve talked to airports and police forces around the UK to make sure they step up patrols and they’re more vigilant, but my message to anybody tempted to follow copycat approach is that if you do this, and you’re caught, you’ll go to jail for a long time.”
On Tuesday, the Government announced a package of measures designed to give police extra powers to combat drones.
The exclusion zone around airports will be extended to approximately a 5km-radius (3.1-miles), with additional extensions from runway ends.
Ministers also announced that from November 30 operators of drones, weighing between 250g and 20kg, will be required to register and take an online drone pilot competency test.
Police will also be able to issue fixed-penalty notices for minor drone offences to ensure immediate and effective enforcement of the new rules.
Fines of up to £100 could be given for offences such as failing to comply with a police officer when instructed to land a drone, or not showing their registration to operate a drone.