British Airways short-haul flights in and out of Heathrow Airport in London have been cancelled until 4pm this afternoon after a plane had to make an emergency landing earlier this morning.

The flight had to return to Heathrow shortly after take-off after smoke was seen billowing from an engine on the Airbus A319. All passengers and crew were unharmed and the pilots have been praised for making a safe landing.

The airport says it is now fully operational and the returning to normal after the incident earlier. But it is says that there may be some disruption throughout the day and that passengers are advised to check the flight status with their airline before travelling to the airport.

British Airways says flight BA762 from Heathrow to Oslo returned to the airport after a "technical fault". The incident is not thought to be terror related.

One person told Sky News "As you looked up you could just see the flames being chucked out of the engine. It was on full fire when we saw it."

One picture shared on Twitter appears to show the engine that was not on fire exposed as it is over-worked.

Emergency vehicles surrounded the plane and emergency chutes could be seen being deployed. There is speculation that the plane had run into a flock of birds.

This eye-witness saw the plane heading towards the airport.