Police clashed with Catalan independence supporters at Barcelona airport during protests on Monday after 12 separatist leaders were sentenced for their part in a failed secession bid in 2017.
Police in riot gear used batons to drive back the crowd near the airport terminal entrance.
Protesters fought back by throwing objects, spraying fire extinguishers and breaking windows.
Health authorities said 53 people were treated for injuries at the airport.
Spain's airport operator, AENA, said at least 108 flights were cancelled.