Two aircraft have been involved in a minor collision at Heathrow.
The incident occurred between an Icelandair and Koreanair plane, and emergency services are at the scene.
No injuries have been reported and no significant impact on arrivals or departures is expected, but passengers are advised to check with their airlines on the status of their flights.
Koreanair flight KE908 was due to depart London Heathrow at 7.35pm on its journey to Seoul.
A picture and video from the scene showed several emergency vehicles on the tarmac.
Dan Sabbagh, The Guardian's defence and security editor who was on board, said he did not feel anything at the time but has been told the wing clipped the other plane's tail while they were taxiing.
He told Sky News: "At first we were told we would have to go back to the stand for a technical reason. Then, after a while, they told us what had happened.
"The atmosphere is calm, just a feeling of mild nuisance."
Mr Sabbagh said passengers are now deboarding at Heathrow.
One social media user who said they were on the Koreanair flight said they thought the plane had scraped another with its wing tip.
A Heathrow spokesperson said: "Emergency services are attending an incident involving two aircraft on the airfield.
"No injuries have been reported, but emergency services are attending to ensure all passengers and crew are safe and well."
London Fire Brigade attended alongside London Ambulance Service (LAS).
A LAS spokesperson said:
"We were called today at 8.06pm to reports of an incident at Heathrow airport.
"We sent a number of resources to the scene including members of our Hazardous Area Response Team (HART), a clinical team leader, a cycle responder and an incident response officer.
"We attended a reception centre for passengers but nobody required treatment or needed to be taken to hospital."
The incident is under investigation.