Update 9.00pm Ousted Catalan leader Carles Puigdemont has described the imprisonment of several of his former Cabinet members in a probe over the region's push for independence as "a serious mistake".
In a speech broadcast late on Thursday by Catalan public TV3, Mr Puigdemont called on Catalans to protest against the Spanish authorities "without violence, peacefully and with respect for everybody's opinions".
Mr Puigdemont and several ousted Cabinet members remain in Brussels, where he said they are seeking "safety and freedom" while judges back in Spain investigate them for pushing Catalan secession.
The prosecutor has asked the National Court judge to issue an international arrest warrant against them.
"The fury with which the Spanish government has attacked a beautiful European nation is outrageous and is threatening us all," Mr Puigdemont said, adding that Catalonia's independence is "no longer an internal affair" of Spain.
The ousted leader reacted to the events at Spain's National Court in Madrid as thousands of protesters took to the streets to protest at the jailings.
Eight of the nine were jailed without possibility of bail while they are investigated on possible charges of sedition, rebellion and embezzlement following the regional parliament's declaration of secession from Spain last week. Bail of €50,000 was set for the ninth.
Protests were called for this evening, and thousands gathered in Catalan towns including Tarragona, Lleida, Girona and Barcelona.
The jailed politicians called for all protests to be peaceful and for their supporters to avoid any show of violence. Mass protests in favour of independence in Catalonia have so far been peaceful.
Under Spain's legal system, investigating judges can order the detention of suspects while a comprehensive probe, sometimes taking months, determines if charges should be brought.
Lawyers said the defendants were serene and wanted the people of Catalonia to stay calm.
Defence lawyer Jaume Alonso-Cuevillas said the decision "lacked justification" and was "disproportionate".
He is representing former regional vice president Oriol Junqueras and four other ousted members of the Catalan Cabinet.
Van den Andreu, the lawyer defending other ex-members of the regional government, said whether his clients were jailed "was already predetermined" before they appeared in court.
Both lawyers said they would appeal the judge's order.
Mr Puigdemont reacted on Twitter to the jailing of nine members of his former Cabinet, posting that "the legitimate government of Catalonia has been jailed for its ideas".
He tweeted the government's "furious clamour" had sent the officials to jail.
"The serene clamour of the Catalans is of freedom," he wrote, posting a photo of protesters in Barcelona.
Update 4.46pm: A Spanish judge has ordered nine ex-members of the government in Catalonia jailed while they are investigated on possible charges of sedition, rebellion and embezzlement.
Investigative magistrate Carmen Lamela issued the ruling on Thursday at the request of prosecutors who are pursuing a criminal case stemming from the declaration of secession the Parliament of Catalonia made on Friday.
The judge set bail for one of the nine former members of the Catalan Cabinet, saying he would be freed if he pays €50,000.
Carles Puigdemont, the former president of Catalonia, and four other ex-Cabinet members are in Belgium and ignored court summonses to appear for questioning.
The Spanish government invoked constitutional authority last week to take over running Catalonia following the region's declaration of independence.
Madrid dismissed the Catalan Cabinet, dissolved the regional parliament and called a new regional election for December 21.
A prosecutor has also asked the National Court judge to issue an international arrest warrant for ousted regional president Mr Puigdemont and four of his ex-ministers.
Update 3.35pm: A Spanish prosecutor has asked a National Court judge to issue an international arrest warrant for Catalonia's ousted regional president and four of his ex-ministers.
The prosecutor made the petition to investigative magistrate Carmen Lamela on Thursday after ex-Catalan president Carles Puigdemont failed to appear in the Madrid court for questioning.
It was part of a rebellion probe following the Catalan parliament's declaration of independence from Spain October 27.
Mr Puigdemont and several of his ministers went to Brussels after the secession declaration and said they would not heed the summons.
Update 1.46pm: Spain's National Court has been questioning ousted Catalan government members in an investigation into possible rebellion charges for having declared the region's independence.
A parallel Supreme Court session for six Catalan lawmakers was postponed for a week.
Prosecutors called on the National Court in Madrid to jail all nine former members of the Catalan government who appeared for questioning.
The request was for unconditional jail for eight of the politicians, while bail could be set for the remaining one. It was not immediately clear how the judge would rule on the request.
Twenty regional politicians, including fired regional government president Carles Puigdemont, were called to appear.
It came after the chief prosecutor demanded they be charged with rebellion, sedition and embezzlement following the Catalan parliament's declaration of secession October 27.
The crimes are punishable by up to 30 years in prison under Spanish law.
The group summoned includes Mr Puigdemont's 13-member former Cabinet and six parliamentary board members.
But Mr Puigdemont, who travelled to Belgium with some of his ex-Cabinet members, remained in Brussels along with four of his former ministers. It could trigger arrest warrants and an extradition petition.
Mr Puigdemont's number two, Catalan ex-vice president Oriol Junqueras, was the first to arrive at the National Court.
The National Court procedures began with the appearance of former Catalan regional government spokesman Jordi Turull, followed by Josep Rull, who had handled the region's territorial affairs.
But a corresponding session in the Supreme Court for six regional parliament members was suspended until November 9 following a request by their lawyers for more time to prepare their defence.
That group includes Catalan parliament speaker Carme Forcadell, one of the leading figures of the pro-independence movement in Catalonia for many years.
Supreme Court judge Pablo Llarena granted the lawyers' request, and ordered the politicians to ensure they are reachable by the police on mobile phones until the hearing next week.
All six left the Supreme Court building in Madrid. Mr Forcadell emerged first followed by the others, who were welcomed by supporters clapping and chanting "Freedom, freedom".
Spain took the unprecedented step of triggering constitutional powers allowing it to take over the running of Catalonia following the region's declaration of independence.
Madrid has sacked the regional Cabinet, dissolved the regional parliament and called a new regional election for December 21.
Mr Puigdemont said he and several of his former ministers went to Brussels earlier this week for "freedom and safety".
Javier Melero, lawyer for some of the separatist lawmakers investigated in the Supreme Court, criticised Mr Puigdemont and other officials' decision to avoid the questioning.
He said the move will be damaging for his clients, the three politicians who are also members of Mr Puigdemont's PDeCAT party.
"Not being at the service of the judiciary when you are summoned is always damaging for the rest of those being investigated," he said.
About two dozen politicians and elected officials from Catalan separatist parties gathered at the gates of the Supreme Court.
"If the question is if in Spain you can trust the judicial system, my answer is no," said Artur Mas, a former president of the Catalan government.
"From the personal point of view and also for my personal experience, I don't think that there are all the guarantees to have a fair trial."
Earlier this year, Mr Mas was banned by a Barcelona court from holding public office for two years after he ignored a Constitutional Court ruling and went ahead with a mock vote on Catalonia's independence in 2014.
Assumpcio Lailla, a former official with Catalonia's Democrats party, said she had travelled to Madrid joining around 100 other politicians and elected officials to show support to those investigated.
"This is an unjust situation in which they are being investigated for facilitating democracy," she said. "I don't understand how Europe can look away from democracy."
The supporters greeted some of the politicians who appeared at the Supreme Court cheering and shouting: "Freedom, Freedom" and "we are not afraid."
Across the street, half a dozen protesters with Spanish flags were stopped by police. They shouted at the Catalan politicians, "cowards" and "to jail, to jail".
In Barcelona, the Catalan regional capital, thousands of people rallied outside the regional presidential palace in Sant Jaume Square at noon to show their support, clapping and chanting slogans in favour of independence.
Earlier story: Spanish prosecutors have asked the National Court to jail eight ex-members of the sacked Catalan government.
The request came after nine ex-ministers were quizzed at the National Court on possible charges of rebellion, sedition and embezzlement.
The case stems from the Catalan parliament's declaration of the region's independence from Spain on October 27.
The court said the prosecutor proposed that jailing the eight may be avoided by paying bail. The judge has yet to decide on the request.
Sacked Catalan president Carles Puigdemont and four other ex-Cabinet members are in Belgium and ignored court summonses to appear on Thursday.
Earlier, the Supreme Court suspended until next week the questioning of six Catalan legislators under investigation for rebellion following the declaration of independence.
The six had been summonsed by two Madrid courts on Thursday and face possible charges of rebellion, sedition and embezzlement.
They include regional parliament speaker and prominent pro-independence activist Carme Forcadell, and 14 ousted Catalan government ministers including Mr Puigdemont.
The Supreme Court said the hearing of the six regional parliament board members was postponed until November 9 following a request by their lawyers.