Ousted Catalan leader Carles Puigdemont has appeared on Catalan TV to urge thousands of pro-independence supporters to protest "without violence" after nine ex-ministers were jailed.
Speaking on Spain's TV3, he called on Catalans to demonstrate against the Spanish authorities "peacefully and with respect for everybody's opinions".
He added: "The fury with which the Spanish government has attacked a beautiful European nation is outrageous and is threatening us all."
Meanwhile, Mr Puigdemont's lawyer has confirmed on Belgian television that an arrest warrant had been issued by the Spanish courts.
Thursday night's protests came after 20 seccessionist leaders were summoned to two courts in Madrid to answer questions - with only 15 turning up.
Judge Carmen Lamela then ordered eight ministers who did adhere with the summons to be jailed unconditionally. A ninth could be set free if they pay a bond of €50,000.
Fired Catalan cabinet members arrive at the national court in Madrid, Spain. From left to right are: Joaquim Forn, Dolors Bassa i Coll, Raul Romeva, Carles Mundo, Jordi Turull, Meritxell Borras and Josep Rull | Image: Paul White/AP/Press Association Images
Reacting to the jailing of his former colleagues on Twitter, Mr Puigdemont said that "the legitimate government of Catalonia has been jailed for its ideas".
Posting with a photo of protesters, he added: "The serene clamour of the Catalans is of freedom."
El clan furiós del 155 ens vol a la presó. El clam serè dels catalans és de llibertat! pic.twitter.com/kdHEaF0aQz
— Carles Puigdemont (@KRLS) November 2, 2017
After Mr Puigdemont's no show in court, the president of the Spanish Supreme Court said it would be "normal" to issue a European arrest warrant, adding to tensions.
The ousted leader's lawyer has said his client would cooperate with the courts and Belgian police if necessary.
"If they ask, he will cooperate with Spanish and Belgian justice," said Paul Bekaert, who ruled out the possibility of his client asking for asylum in Belgium by saying it was "off the table".
Lawyers for the nine detained former ministers said they planned to appeal the move and insisted they wanted the people of Catalonia to stay calm.
The Supreme Court has adjourned hearings until 9 November to give them time to prepare a defence.
The National Court has also been questioning the ousted Catalan parliament members - with former regional government spokesman Jordi Turull and minister for territorial affairs Josep Rull appearing there on Thursday.
Mayor of Barcelona Ada Colau and other members of Barcelona City Council hold a protest in front of the Palau de la Generalitat in support of defendant Catalan politicians | Image: Jordi Boixareu/Zuma Press/PA Images
An investigation could take years before it leads to a trial.
Mr Puigdemont, and 19 others, face charges of rebellion, sedition and misuse of public funds.
The crimes being investigated are punishable with up to 30 years in prison under Spanish law.
An arrest warrant makes it virtually impossible for Mr Puigdemont to stand in a snap election, called for December 21st, after the Catalan government was dissolved by Spain in light of the vote for independence.
The Spanish Prime Minister Mariano Rajoy dissolved the Catalan regional parliament hours after it made a unilateral declaration of independence last Friday.
Madrid has declared the October 1st independence referendum - which voted in favour of separating from Spain - illegal and unconstitutional.
The Spanish Constitutional Court has also found the Catalan parliament’s independence declaration to be illegal.
The struggle has deeply divided both Spain and Catalonia – with polls suggesting that less than half of Catalan’s support independence.
An official regional survey published on Tuesday found that nearly 49% of Catalans believe the region should be independent.
That figure is up from the 41% recorded in June and is at its highest since December 2014.
The upcoming December 21st elections could provide the most accurate indication of how the Catalan people would like to move forward - however any outstanding charges blocking separatist leaders from standing would seriously undermine the process.
Additional reporting: Jack Quann