A German court has ordered former Catalan President Carles Puigdemont to remain in prison pending a decision on an extradition request from Spain.

Puigdemont was arrested after he crossed from Denmark into Germany on his way to Belgium where he fled after the Spanish national government imposed direct rule over Catalonia after Catalonia's leaders declared independence on October 27, 2017.

Spain issued a European arrest warrant for the former leader on Friday. Spanish prosecutors have sought to charge Puigdemont with sedition and rebellion.

Puigdemont appeared "calm and tranquil" at his hearing, Georg-Friedrich Guentge, prosecutor from the German state of Schleswig-Holstein, said on Monday.

A tracking device was reportedly placed in Puigdemont's car by Spanish investigators.

He was on his way back from a trip to Helsinki, Finland, when German authorities detained him, presumably with the help of the geolocation information.

Wave of protests

After the European arrest warrant was issued on Friday, a wave of protests erupted in the region.

Roughly 55,000 people took to the streets in central Barcelona, according to estimates from Spanish news agency Efe.

Smaller demonstrations were held in several other cities across Catalonia.

The protesters in Barcelona marched between the central offices of the European Commission and the German consulate, venting their anger over the arrest.

Thousands of protesters also responded to the Committees for the Defence of the Republic and other groups' calls and gathered in front of the Spanish government's Catalonia delegation, where clashes with police ensued.

At least 89 people were injured in clashes and four arrests were made.

Tensions in Catalonia remain high and its separatist leaders abandoned plans to name a new president after the arrest on Friday of the latest candidate, Jordi Turull, sparked protests in Barcelona.

Puigdemont's Belgian lawyer thinks his client will be released soon under conditions. He would then be able to fight the extradition request for freedom.

The president of the Catalan independence movement ANC made an urgent appeal to the European Union, and in particular to Germany, not to extradite Puigdemont to Madrid. Supporters of the separatist leader have announced more demonstrations.

Puigdemont will remain in the Neumunster prison in the country's north until German authorities decide on his extradition.