Barcelona — Carles Puigdemont, the fugitive ex-leader of Catalonia and ardent separatist, was arrested Sunday by German police on an international warrant as he tried to enter the country from Denmark.Puigdemont was on his way back to Belgium where he has been staying since fleeing Spain following a failed bid by his regional government in October to declare independence from Spain, said his lawyer, Jaume Alonso-Cuevillas.The Spanish government told The Associated Press it had received "official confirmation from German authorities of the arrest" of Puigdemont in response to the warrant issued by Spain's Supreme Court.Spanish state prosecutor said it was in contact with its German counterparts to carry out its request to extradite Puigdemont to Spain, where he faces charges including rebellion that could put him in prison for up to 30 years.German highway police arrested Puigdemont on Sunday morning near the A7 highway that leads into Germany, police in the northern state of Schleswig-Holstein said. State prosecutors in the northern town of Schleswig are now in charge, but they couldn't be immediately reached for further details.German news agency dpa said that Puigdemont was taken to a prison in the northern town of Neumuenster. Dpa photos showed a van with tinted windows believed to be carrying Puigdemont as it arrived at the prison. Video footage also showed the same van leaving a police station in Schuby near the A7 highway.A Spanish police official told the AP under customary condition of anonymity that Spain's National Center for Intelligence and police agents from its international cooperation division helped German police to make the arrest.Dpa reported that deputy state prosecutor Ralph Doepper, who is based in the northern town of Schleswig, said that a German court would likely decide by Monday whether Puigdemont would remain in custody pending the outcome of his extradition case.Doepper said that "we are at the very beginning of our assessment." He added: "we had information that he would be in Germany or would enter Germany."A Spanish Supreme Court judge reactivated an international arrest warrant for Puigdemont on Friday when he was visiting Finland. Spain has also issued five warrants for other separatist who fled the country.Grassroots groups both for and against Catalan secession have called for protests later on Sunday in Barcelona. The pro-independence National Catalan Assembly has called on its supporters to march from office of the European Commission to the German Consulate, while pro-Spain supporters will gather at the office of Spain's government representative for Catalonia.Puigdemont, 55, is a former journalist and mayor of Girona who was thrust to the forefront of Catalonia's independence push when he was handpicked by predecessor Artur Mas to become regional president in 2016. He withstood intense political pressure from Spanish Prime Minister Mariano Rajoy and Spain's courts as he piloted the secession bid.Spain was plunged into its worst political crisis in three decades when Puigdemont's government flouted a court ban and held an ad-hoc referendum on independence for the northeastern region in October.The Catalan parliament's subsequent declaration of independence received no international recognition and provoked a takeover of the regional government by Spanish authorities that they say won't be lifted until a new government that respects Spain's Constitution is in place.Spain had originally asked for Puigdemont's extradition from Belgium after he moved there, but later withdrew the request until judge Pablo Llarena concluded his investigation this week. Llarena ruled that a total of 25 Catalan separatists would be tried for rebellion, embezzlement or disobedience.In the meantime, Puigdemont was free to make trips to Denmark, Switzerland and Finland, as part of his effort to gain international support for the secessionist movement.Puigdemont was also able to successfully run a campaign as the head of his "Together for Catalonia" bloc in a regional election in December in which separatist parties maintained their slim majority in Catalonia's regional parliament.He had wanted to be re-elected as Catalonia's regional president — albeit while remaining abroad to avoid arrest — but eventually was stopped by a Spanish court.Separatists in Catalonia are currently trying to elect a leader for the regional government before a two-month time limit is up and new elections are called.Spain's Constitution says the nation is "indivisible" and any changes to its top law must be made by its national parliament in Madrid.Nine people who promote Catalan secession have been placed in pre-trial custody to prevent what Llarena considered a flight risk or intention to continue with independence efforts.Polls show Catalonia's 7.5 million residents are equally divided over secession, although a majority support holding a legal referendum on the issue.