Spanish police have removed more than 100 Belgian students from a plane that was due to fly from the Canary Islands to Belgium.
The Irish budget airline Ryanair says police were called after the university students became disruptive.
They refused to carry out instructions after some objected to being charged a fee for excess hand luggage, it said.
Most of the students are now stranded in Lanzarote because other flights are either full or too expensive.
Spanish newspaper La Provincia said airline staff had tried to charge one passenger extra for carry-on baggage and his friends on the plane "mutinied".
A spokesman for the Spanish interior ministry said the pilot was preparing for takeoff at Guacimeta airport bound for Charleroi, Belgium, when she radioed for police assistance.
The spokesman said that of the 168 passengers on board, fewer than 70 were allowed to re-board the flight.
Ryanair confirmed that passengers "became disruptive and refused to comply with crew instructions" over a fee for outsized luggage.
In a statement, it said police had required the entire aircraft be off-loaded and each passenger identified.
"Following further disruptive behaviour, the police required for security reasons that this entire group be refused travel," the statement said.
Some of the students - from the University of Brussels - were later able to find alternative flights, but about 70 were still stuck on Lanzarote on Sunday evening.