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Stansted Airport has cancelled all departing flights until midnight on Friday evening after a passenger shuttle bus caught fire.
The blaze - caused by an electrical fault - lead to part of the main terminal being evacuated as thick black smoke affected "much of the front of the terminal building", Essex Fire service said.
No injuries are reported to have occurred.
Eyewitness videos show the fire engulfing the bus near the main terminal forecourt.
The fire has since been extinguished but passengers due to depart this evening are being told to contact their airline directly for up-to-date flight information and many are now being re-screened through security.
The bank holiday travelers expressed their dismay at how the evacuation had been handled, on social media.
Taylor Fulton-Ward, 18, from Hertfordshire, who was flying to Dublin with her family for the Easter weekend, said people were "pushing and panicking" after certain doors were not open to allow people to leave.
She said: "We arrived at the airport and after a lot of waiting we got through security and staff told us all flights were running but delayed.
"After an hour, our flight disappeared from the board with no communication. We went back through to check in to try and re-book the flight but the crowds were crazy.
"Announcements were telling us to leave the building, but the doors were not open - so people began pushing and panicking.
"The biggest problem was not being able to get out the doors and a lack of communication."
It comes on one of the busiest days of the year so far for the Essex airport as people get away for the Easter break.