A British Airways flight had to be evacuated after “a horrible white acrid smoke” poured into the cabin 10 minutes before it landed in Valencia, Spain.
The airline said flight BA422 had "experienced a technical issue on its landing approach into Valencia".
The 175 passengers, six cabin crew and two pilots were all evacuated safely via the emergency slides, and were met by the airport’s emergency services.
Three customers were taken to hospital and have since been discharged.
Gayle Fitzpatrick, from Glasgow, was on the flight with her husband Stephen and shared footage of the “very frightening experience” on Twitter.
She said she had heard rumours an "air conditioning unit" may have been to blame.
Describing the scene, she said: "It was very scary. The flight was just ending, and with 10 minutes to go the flight started descending rapidly as smoke started to fill the cabin.
"There were no communications from the crew, some of which started to wear full oxygen masks and protective fire wear."
She continued: "Eventually they managed to open the emergency doors and told us to go down the chutes.
"There were fire engines waiting and then we were all ushered into a bus then to the airport.
"We are still waiting to hear what happened. People were crying and hyperventilating. It was genuinely scary."
Mrs Fitzpatrick added that passengers were not told it was an emergency until after they had landed.
After the evacuation, she said passengers had been waiting at the airport for two hours "without any information at all" before later being told they could go and collect items from the plane.