Passengers on a British Airways flight faced a nightmare scenario as the cabin filled with ominous thick white smoke before the jet was forced to make an emergency landing in Spain.
One terrified passenger likened the flight to a horor film: "Terrifying experience on flight to Valencia".
Video on social media purportedly shows the cabin of the BA jet engulfed with smoke so dense passengers could barely see.
The plane made an emergency landing at the airport, but the doors remained closed for many more minutes, angry passengers lament on Twitter, according to the Daily Mail.
"There were fire engines waiting and then we were all ushered into a bus then to the airport".
"The flight crew from British Airways haven't said anything to us". Felt like horror film.
Once the Airbus A321 landed safely at the Spanish airport, crew members deployed the inflatable emergency slides and evacuated passengers. No water, no first aid.
A spokesman for the airline said on Monday evening: "We can confirm that British Airways flight BA422 from Heathrow to Valencia has been involved in an incident today". People were crying and hyperventilating.
The plane, which took off from London Heathrow earlier this afternoon, managed to land in Valencia, but it's still not confirmed what has caused the smoke.
Other passengers claimed their oxygen marks did not fall down, meaning they could not use them, despite the efforts of the flight attendants.
No injures have been reported and aviation authorities have said everyone on board is safe.
"British Airways teams are assisting customers who are in the airport terminal".