Heathrow Terminal 3 was partially evacuated on Monday afternoon (October 16).
The fire alarm went off at around 2.30pm and passengers were "ushered out" of the terminal.
We'll be bringing you all the latest updates as we get them.
Keep up to date with the latest news from west London via the free getwestlondon app.
You can set up your app to see news and events from your area, and receive notifications for any breaking news.
'A precautionary measure'
A spokesperson for the airport said passengers did not leave Terminal 3 while the alarm was investigated. She said they were moved from the affected area of the terminal to a different area within the airport.
She said it was “a precautionary measure”
View from the airport
'Fire alarm going off'
She said they were ushered out after a fire alarm sounded
Video from the airport
This video was posted on twitter by @a_ljb
Comment from Heathrow
A Heathrow Airport spokesperson said part of the terminal was evacuated after a fire alarm sounded.
However, there was “no fire or smoke” and the situation was stood down at around 3.10pm
This video shows a sea of people ‘going out’ of Terminal 3 while a siren sounds
Terminal 3 'partially evacuated'
Passengers in Heathrow have reported part of Terminal 3 has been evacuated