NATIONAL NEWS: Fire alarm CLOSES London Heathrow airport

Emergency services were called to the scene and both inbound and outbound flights were put on hold.

Parts of the airport building were evacuated as was the control tower, but an airport spokesperson later confirmed normal service had resumed.

Despite only being suspended for about an hour, it is likely thousands of passengers had flights delayed or cancelled, and other travellers will have missed connecting flights.

The airport has not yet revealed the cause of the alarm but apologised for the inconvenience it had caused.