Thousands of people began marching in Barcelona on Sunday to protest the jailing of nine Catalan separatist leaders facing trial on "rebellion" charges.
Many chanted "Freedom for the political prisoners" as they massed on the Parallel Avenue, one of the city's main streets, wearing yellow scarves, sweaters or jackets, the color chosen to show solidarity with the jailed leaders.
The march was called by a platform set up in March to "defend Catalan institutions" and "the rights and fundamental freedoms" of its citizens.
The protest was backed by the Catalan branches of Spain's two largest trade unions, the CCOO and the UGT, sparking unease among union members who oppose independence for the wealthy northeastern region.
"There have been tensions (among union members) just like in the rest of the Catalan society," the secretary general of the Catalan branch of UGT, Camil Ros, told AFP on Saturday on the eve of the march.
"But it is not a separatist protest. It is time to build bridges and the Catalan problem cannot be solved through the courts but by dialogue and politics," he added.
The demonstration comes ten days after a German court dismissed an extradition request for Catalonia's ousted separatist president Carles Puigdemont on grounds of rebellion and released him on bail.
Spanish prosecutors last week handed over new information to Germany they hope will prove the use of violence which would justify the rebellion charge against Puigdemont and their extradition request.
Puigdemont is also accused of misuse of public funds for staging an independence referendum in Catalonia on October 1 despite it having been ruled unconstitutional by the courts.
Alex de Ferrer, a 50-year-old IT specialist, said he planned to take part in the protest because jailing separatist leaders "only serves to manufacture separatists".
The independence movement is "a bit decapitated" following the arrests of its leaders but "this is temporary", added de Ferrer, who supports leftist separatist party ERC, whose leader Oriol Junqueras is in jail.
Across Catalonia people are wearing yellow ribbons or displaying posters of yellow ribbons from their balconies and windows in sign of support for the nine jailed separatist leaders, who they consider to be "political prisoners".
Spain's justice minister, Rafael Catala, has called the use of yellow ribbons "insulting", arguing there are no political prisoners in Spain, instead there are "politicians in prison".
Since October 16 the leaders of Catalonia's two largest pro-independence groups, Jordi Sanchez of the ANC and Jordi Cuixart of Omnium Jordi Cuixart, have been in jail while they await their trial for rebellion.
Prosecutors say the two men played central roles in orchestrating pro-independence protests in September in Barcelona which trapped national police inside a government building and destroyed their vehicles.
They are also accused of mobilizing thousands of pro-independence supporters to prevent police from stopping the October 1 independence referendum from going ahead.
"What makes me sad is the accusation of violence, which never existed," Sanchez said in December on Twitter.
He was elected as a lawmaker in snap polls in Catalonia in December and has been proposed two times as a candidate to lead a new Catalan regional government but a judge refused both times to allow him to leave jail to be sworn in.
Six other Catalan separatist leaders are in jail in Spain for rebellion, along with Junqueras and the leaders of the grassroots separatist groups.
Catalonia has been in political limbo since Spain's conservative central government imposed direct rule on the region after it unilaterally declared independence in October.
Fresh regional elections will be triggered if a new leader is not elected by May 22.