BERLIN — Authorities in Germany arrested former Catalan president Carles Puigdemont on Sunday after he crossed into the country from Denmark, setting up a possible extradition of the separatist leader to Spain. 

Puigdemont’s attorney announced the arrest on Twitter and said his client had been taken to a police station. German police confirmed in a statement that Puigdemont had been arrested at 11:19 a.m. Sunday by highway patrol officers in Schleswig-Holstein, a state that borders Denmark.

German authorities did not immediately say what they intend to do with Puigdemont. Spain could demand his extradition under the terms of a European treaty.

The arrest marked the latest in a series of maneuvers that have left Catalonia’s independence movement with few leaders who are not either being held in custody or sought as fugitives.

Puigdemont is wanted in Spain on charges of rebellion and sedition arising from his role in organizing an October referendum on Catalan independence. If convicted, he could face as many as 30 years in prison.

The Catalan leader has been living in self-imposed exile in Belgium since he fled Spain five months ago amid the uproar over the referendum. Separatists won that vote, and Puigdemont’s government declared independence. But the Spanish government deemed the ballot unconstitutional and imposed direct rule. 

Spain had reactivated an international arrest warrant for Puigdemont on Friday. At the time, he was in Finland. But his attorney, Jaume Alonso-Cuevillas, said Saturday that Puigdemont had left Finland and was en route back to Belgium. 

Puigdemont’s attorney said that German police have been following proper procedures since the arrest and that his client had intended upon his return to Brussels to “put himself, as always, at the disposal of the Belgian justice system.” 

[Catalonia finally declared independence — but Spain vows it won’t last long]

The detention comes at a tense moment in Catalonia. Separatists hold a majority in the regional parliament in the wake of elections in December. But they have not been able to form a government and have abandoned plans to name a new president after the arrest of their latest candidate, Jordi Turull.

Puigdemont had sought to reclaim the presidency for himself but abandoned that bid on March 1, announcing in a 13-minute video that he had come to the decision with “the greatest sadness.” 

But he also said that he would set up a foundation that had the makings of a government-in-exile.

“I will not throw in the towel. I will not quit. I will not give up in the face of the illegitimate behavior of those who lost at the ballot box,” he said.

That message was in contrast to the one he had communicated privately to a colleague in messages that were captured by a TV camera and that acknowledged that the Spanish government’s crackdown “has won.”

“I guess that you’ve realized that this is over,” reads one of the messages.