BARCELONA, Spain — Riot police engaged in a running battle with protesters outside Barcelona's airport Monday after Spain's Supreme Court convicted 12 separatist leaders of illegally promoting the wealthy Catalonia region's independence and sentenced nine of them to prison.
Police fired foam bullets and used batons against the thousands of protesters who converged on Josep Tarradellas Barcelona-El Prat Airport after a pro-independence grassroots group put out the call. Protesters fought back by throwing objects, spraying fire extinguishers and breaking windows.
Regional emergency service SEM said 53 people were treated for injuries at the airport. Spain's airport operator, AENA, said at least 108 flights were canceled.
Police also clashed with angry crowds late Monday night in downtown Barcelona. They used batons, and sounds similar to the firing projectiles were heard.
Nine of the 12 Catalan politicians and activists were found guilty of sedition and given prison sentences of nine to 13 years. Four of them were additionally convicted of misuse of public funds.
The other three were fined for disobedience. The court barred all of them from holding public office.
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All 12 were acquitted on the more serious charge of rebellion, which implied the use of violence, brought by state prosecutors and lawyers for the far-right Spanish party Vox. Vox leader Santiago Abascal criticized the verdict as too light.
Spain's caretaker prime minister, Pedro Sánchez, said the outcome of the four-month trial proved the 2017 secession attempt had become "a shipwreck." Sánchez urged people to "set aside extremist positions" and "embark on a new phase" for Catalonia.
He said he hoped the prison sentences would mark a turning point in the long standoff between national authorities and separatist lawmakers in Barcelona, the Catalonia region's capital.
The Catalan separatist movement is going through its most difficult period in years. With a general election scheduled for Nov. 10, its most charismatic leaders are behind bars or abroad after fleeing to avoid prosecution.
But secessionists were defiant after the Supreme Court issued its decision in Madrid, taking to the streets, halting some trains by placing burning tires and wood on tracks, and blocking roads as well as the airport entrance.
Former regional president Carles Puigdemont, who fled to Belgium in October 2017 with several others when they were summoned to appear in court, said the upcoming general election is an opportunity to show "a massive response of rejection" for the court's verdict and the "dignity and firmness" of the Catalan independence movements.
Puigdemont spoke in Brussels hours after a Spanish Supreme Court judge issued an international warrant for his arrest.
Andrew Dowling, an expert on contemporary Spanish politics at Cardiff University in Wales, said the sentences are "going to make a bad situation worse."
"It's going to create a terrible wound in Catalan society until these people are released," he said by telephone.
Catalan identity is a passionate issue in the northeastern region bordering France, but elsewhere it has failed to capture the public imagination and, crucially, lacked international support.
At the center of the prosecutors' case was an Oct. 1, 2017 independence referendum that the Catalan government held even though the country's highest court had prohibited the vote.
The "yes" side won, but because it was an illegal ballot most voters didn't turn out and the vote count was considered of dubious value. The Catalan Parliament, however, unilaterally declared independence three weeks later, triggering Spain's worst political crisis in decades.
The Spanish government stepped in and fired the Catalan regional government, with prosecutors later bringing charges.