Armed police have been spotted at Heathrow Airport’s Terminal 3 Car Park after what’s been described as a major ‘incident’.

The London Ambulance Service said a “significant incident” was declared at around 8.40am.

Reports on social media suggest people were being told to stay in their cars in case of gas being sprayed.

One man has been filmed in handcuffs surrounded by armed officers.

The Heathrow Express and parts of the Elizabeth Line were suspended but are now running with delays.

Both Spur Roads and the M4 Westbound exit slip-road at Junction 4 were closed but have reopened and are now stop-start.

Heathrow is advising passengers to allow extra time when travelling to the airport and to check with their airline for any queries.

Police are not treating this as a terror incident.

Policing commentator Graham Wettone explains why there’s a huge armed presence.