Catalonian regional police arrested nine people on Sunday in protests that erupted in Barcelona over the arrest earlier in the day in Germany of former regional President Carles Puigdemont as per a European arrest warrant issued by the Spanish judiciary.

The Mossos d'Esquadra - the Catalonia police - said that the nine people arrested were taken into custody for the crime of attacking authority during the protest, in which 98 people were reported injured, 90 of them in Barcelona and eight elsewhere in Catalonia, according to local emergency services.

The police also said that those arrested were slightly injured during the incidents - or while being taken into custody - adding that 13 regional police officers are among the 90 others injured in Barcelona.

The incidents - consisting of much pushing and shoving, as well as other confrontations - took place near the offices of the Catalonian government, where anti-riot police fired warning shots to prevent some demonstrators, who were hurling objects including trash at them, from breaking through the police cordon protecting the building.

Demonstrators also headed for the German consulate on Puerto Olimpico in Barcelona.

Groups of independence-minded protesters cut roads and streets elsewhere in Catalonia such as in Gerona, where Puigdemont used to be mayor.

Puigdemont was detained earlier on Sunday as he attempted to cross the German border after a European arrest warrant was issued by Spain, where he faces charges of rebellion and sedition, German police confirmed.

The former Catalonian regional president's lawyer said he was being held at a police station in Germany and had been detained as he made his way by car back to Belgium, the country he fled to in October after the Spanish judiciary announced it would be investigating him for his alleged part in organizing a separatist referendum and the subsequent declaration of independence.

A spokesperson for the Kiel city criminal police, Uwe Keller, told EFE that Puigdemont was picked up at 11:19 am (local time) on a road that connects Germany and Denmark and local media reported that he had been transferred to a prison in the northern town of Neumunster.

Judicial sources confirmed to EFE that Germany now has up to 90 days to decide whether to extradite Puigdemont to Spain, a move to which he is opposed as he believes he would not get a fair trial there.

He had been in Finland to give a talk but left on Friday after the Spanish judiciary reactivated the European arrest warrant.

Puigdemont and his government were removed from their posts after the Spanish Senate activated Article 50 of the Constitution, which saw the Catalonia region's autonomy reeled back in response to its earlier declaration of independence.

The Spanish judiciary has formally filed rebellion charges against 13 people allegedly involved in Catalonia's failed bid for independence, nine of whom are also facing charges of misuse of public funds.

Arrest warrants have been issued for at least four people who fled the country, while many other remain in pre-trial detention, including former Vice President Oriol Junqueras.