BARCELONA/BERLIN (Reuters) - Former Catalan leader Carles Puigdemont was detained in Germany on Sunday, five months after entering self-imposed exile from Spain, where he faces up to 25 years in prison for organizing an illegal secession referendum last year.

Puigdemont had entered Germany from Denmark after leaving Finland on Friday when it appeared that police would arrest him there and begin an extradition process requested by Spain.

The detention threatens to worsen the Catalan crisis that flared last year when the region made a symbolic declaration of independence, prompting Madrid to take direct rule.

Tens of thousands of Catalans, many of them wearing yellow in support of jailed separatist leaders, demonstrated in Barcelona on Sunday afternoon, chanting “Puigdemont, our president” and “freedom for political prisoners.”

In a smaller parallel protest outside the central government delegation in the Catalan capital, three people were arrested and 50 suffered minor injuries after protesters clashed with riot police.

Catalan parliament speaker Roger Torrent called for a broad coalition in defense of civil liberties and sovereign rights in a televised address on Sunday evening.

“No judge, no government and no civil servant has right to

charge and pursue the president of all Catalans,” he said. Torrent called for “calm and responsibility” following the scuffles.

Spain’s Supreme Court ruled on Friday that 25 Catalan leaders would be tried for rebellion, embezzlement or disobeying the state and reactivated international arrest warrants for Puigdemont and four other politicians who went into self-imposed exile last year.

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Among those subject to the arrest order, Clara Ponsati, a former Catalan minister now living in Scotland, told authorities she would turn herself in, Scottish police said in a statement on Sunday afternoon.

The other three Catalan leaders are in Belgium.

German police arrested Puigdemont on Sunday in the northern state of Schleswig-Holstein on a European arrest warrant issued by Spain. In a statement, police said Puigdemont was detained near a section of the A7 highway, which cuts through the state from the city of Flensburg near the Danish border.

Puigdemont was later transferred to Neumuenster prison, German news agency DPA reported.

German magazine Focus said that Spanish intelligence informed the BKA federal police that Puigdemont was on his way from Finland to Germany. It gave no source for its report.

He had arrived in Finland on Thursday to meet lawmakers and attend a conference as part of a campaign to raise the profile of the Catalan independence movement in Europe.

EXTRADITION ISSUE

The Higher Regional Court in Schleswig-Holstein will be responsible for deciding whether to grant Spain’s extradition request.

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The European arrest warrant system in place since 2004 makes it easier for EU countries to demand extradition from other EU states, having removed political decision-making from the process. EU nations issue thousands of such warrants each year.

Puigdemont will appear in court tomorrow to have his remand extended, German prosecutors said in a statement.

Paul Bekaert, who represents Puigdemont in Belgium, where he had been subject to an arrest warrant in December, said his client rang him after being detained in Germany and had appeared calm during the conversation.

Bekaert told Reuters TV that his client would have to appear before a German judge within 48 hours to determine whether or not to keep him in custody. Puigdemont will take German legal representation, Bekaert said, with the whole legal process, including possible appeals, likely to take months.

Puigdemont could take his case to Germany’s highest court, which in 2005 blocked the extradition to Spain on an EU arrest warrant of a German-Syrian al-Qaeda suspect.

The case of Mamoun Darkazanli sparked a judicial row between the two countries after Germany’s Federal Constitutional court refused to turn over Darkazanli, saying that EU extradition laws designed to speed up the delivery of suspects between member states violated the rights of German citizens.

Puigdemont has previously made clear his preference to fight the extradition process from Belgium, where the former Catalan leader was heading at the time of his detention, according to Puigdemont’s spokesman, Joan Maria Pique.

“The president was going to Belgium to put himself, as always, at the disposal of Belgian justice,” Pique told Reuters.

The Spanish Supreme Court had issued an international arrest warrant against Puigdemont last year but withdrew it in December to avoid the risk of Belgian authorities granting him asylum.

Leaving Belgium had exposed him again to the risk of arrest.

Supreme Court judge Pablo Llarena also sent five separatist leaders to pre-trial jail, sparking protests across Catalonia.