Two aircraft were involved in a minor collision at Heathrow.
The incident happened between Icelandair and Koreana aircraft and emergency services are on the scene.
No injuries were reported and no significant impact on arrivals or departures is expected, but passengers are advised to check with their airlines about the status of their flights.
KoreanAir flight KE908 was scheduled to depart London Heathrow for Seoul at 7.35pm.
A photo and video from the scene showed several emergency vehicles on the tarmac.
Dan Sabbagh, defense and security editor of The Guardian, said he did not feel anything at the time but was told that the wing clipped the tail of the other plane as it taxied.
He told Sky News: “First we were told we had to go back into the stands for a technical reason. Then, after a while, they told us what happened.
“The atmosphere is calm, with only a slight sense of disturbance.”
Passengers are now disembarking at Heathrow, Mr Sabbagh said.
A social media user who said they were on a Koreana flight said they thought the plane had scraped another with its wing tip.
A Heathrow spokesman said: “Emergency services are attending an incident involving two aircraft at 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 the London Ambulance Service (LAS).
A spokesperson for LAS said:
“At 8.06pm today we were called to reports of an incident at Heathrow Airport.
“We sent several resources to the scene including our Hazardous Area Response Team (HART), a clinical team leader, a bicycle responder and an incident response officer.
“We went to a reception center for passengers but nobody needed treatment or needed to be taken to hospital.”
The incident is under investigation.