Flights have resumed at London’s Heathrow Airport after it grounded arrivals and departures following reports of a drone sighting.
Europe’s busiest airport said it was working with police to ‘prevent any threat to operational safety’.
Planes finally started to take off again at 6.30pm, but it was unclear how many flights would be delayed in the coming hours after the runway was closed just after 5pm.
Many travellers were left waiting on the tarmac of the airport, which is the UK’s largest, serving more than 200,000 people every day, for around 90 minutes.
Angry passengers took to Twitter to express their frustration.
One user said: ‘Currently stuck on the runway at Heathrow. Why do the drone people keep doing this?. #heathrow #drones #dronelife.’
Another user wrote: ‘Citizens of the UK should be rather worried that the presence of a real or imaginary flying helicopter toy can outwit and bring an entire airport to a standstill.’
Cassandra Fairbanks was due to fly out on the 5.05pm flight from London to New York. She said her plane was sitting on the runway for an hour and a half.
She told the London Evening Standard: ‘The pilot just said that they have no updates.
‘All he said was that there was drone activity and all flights are grounded. There is no estimate on how long it will be before we can move.’
A Heathrow spokeswoman told 89.7 Bay: ‘We continue to work closely with the Met Police to respond to reports of drones at Heathrow.
‘We continue to monitor this situation and apologise to any passengers that were affected by this disruption.’
The news comes just weeks after more than 1,000 flights and 140,000 passengers were affected in the run up to Christmas amid drone chaos at Gatwick Airport.
Several British Airways, Air Malta and Easyjet flights to Malta were disrupted.
Heathrow is the busiest airport in Europe with more than 78 million people passing through its terminals last year.