More than 70 scheduled departures on Wednesday were cancelled as a result, and around the same number of arrivals. The airport has said flights would be suspended until at least 3pm on Wednesday.
“Following last night’s car fire in Terminal Car Park 2, emergency services have now downgraded the incident, but remain on the scene as a precaution,” the airport said.
“The teams have worked hard to get the airport operational, with the first passengers now re-entering the terminal and the first flights expected to depart from 3pm.”
It added the Dart shuttle train remained out of service, with replacement buses operating between the terminal and Luton Airport Parkway station. "Additional staff remain on hand to assist passengers across the airport,” the airport said.
Firefighters from Bedfordshire Fire and Rescue were called to the scene at around 8.45pm and by 9.30pm on Tuesday were dealing with a "rapidly escalating fire".
Chief fire officer Andrew Hopkinson told the BBC it is thought the fire started in a diesel car before spreading through the car park. He added up to 1,500 vehicles may have been in the car park at the time of the fire.
Four firefighters and a member of airport staff were taken to hospital for treatment for smoke inhalation, with another person treated and discharged at the scene. An investigation into the cause of the fire is under way.
