All flights from London's Heathrow Airport were halted for about an hour on Tuesday (local time) after the airport said there had been sightings of a drone near Europe's busiest air hub.
- Flights were halted for one hour as a precautionary measure
- The Transport Minister is prepared to deploy military-grade equipment
- It comes three weeks after Gatwick cancelled 1,000 flights due to drone sightings
"We are responding to a drone sighting at Heathrow," the airport said.
"As a precautionary measure, we have stopped departures while we investigate. We apologise to passengers for any inconvenience this may cause."
Flights resumed after about an hour, Heathrow said.
Transport Minister Chris Grayling had been in contact with the airport concerning the drone sighting.
"The military are preparing to deploy the equipment used at Gatwick at Heathrow quickly should it prove necessary."
London's second busiest airport, Gatwick, was severely disrupted when drones were sighted on three consecutive days in December, resulting in about 1,000 flights being cancelled or diverting and affecting 140,000 passengers.
Heathrow and Gatwick responded by ordering military-grade anti-drone defences worth "several million pounds".
Heathrow said earlier this month it was working closely with authorities including the police and looking at relevant technology to combat the threat of drones.