Pro-separatist marchers clashed with riot police in Barcelona, Spain during a demonstration Sunday against the arrest of Catalonia's former president Carles Puigdemont.
Police swung batons to stop protesters from marching on the Spanish government offices. The marchers threw garbage and other objects at the officers. At least 50 people were hurt.
Thousands filled the streets of the Catalan capital in support of the ousted president and separatist leader who was picked up on an international arrest warrant in Germany Sunday. He had just crossed the border from Denmark.
Puigdemont is expected to appear in court in Schleswig Monday while German prosecutors consider Spain's extradition request.
Puigdemont is wanted in Spain on charges of treason and inciting violence. He fled Spain for Belgium in October.
He defied the warnings of the central Spanish government in Madrid and held a referendum on Catalonian secession.
The Catalan parliament declared independence, leading to a violent crackdown by police and a takeover of the Catalan government by Madrid.
Pro-independence lawmakers won a slim majority in December's parliamentary elections in Catalonia. But parliament has been unable to name a new president and the future of independence is murky.
Puigdemont had urged the Catalan parliament to choose pro-independence ally Jordi Sanchez as the new regional president.
But Sanchez is in jail in Madrid while prosecutors mull over whether to also formally charge him with sedition and rebellion.
The Spanish Supreme Court decided Friday to charge 13 Catalan separatist leaders with rebellion.
Catalonia, in northeast Spain, and its capital Barcelona are major tourist magnets. It has his own language and distinct culture. But the separatist crisis has hurt tourism and the regional economy.
Catalan separatists say the region is a powerful economic engine that drives Spain and have demanded more autonomy.
Those who want to stay united with Spain are afraid the region will sink into an economic abyss without the central government, its ties to the European Union, and its numerous existing bilateral relations.