DFDS Vice President Gert Jakobsen told ITV News that 15 passengers and eight crew members were treated for smoke-related injuries on the King Seaways ferry following a fire on board.
Four crew members and two passenger were later taken to Scarborough Hospital by helicopter for further treatment. Police are investigating the incident.
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After a lively start to the long weekend with torrential, thundery downpours - a drier night.