Disruption at Heathrow Airport as control tower evacuated after fire alarm
The alarm on the airfield meant several flights were unable to land or take-off from the airport.
Flights were forced to divert to Gatwick and Stansted airports, while some had to return to their original destinations after take-off.
Heathrow Airport said the alarm has been investigated, and "operations" have started to resume.
A spokeswoman for the National Air Traffic Services (NATS) said: "the control tower had been evacuated" after an alarm was triggered.
Heathrow Airport has tweeted to apologise for the delays: "There has been a fire alarm activation on the airfield which emergency services are currently responding to. We’re sorry for the delay, hopefully we’ll have more information for you soon." ■