According to police figures, some 525,000 people took to the streets of the regional capital on Friday, with many of the protesters marching from different parts of the Catalonian region, whose government had launched an unsuccessful bid for secession from Spain in 2017, reports Efe news.
The protest was held under the slogan "For Rights and Freedoms, General Strike", and dominated by the ubiquitous yellow ribbon - the symbol used to call for the release of the nine Catalan leaders that were convicted of sedition and misuse of public funds by Spain's Supreme Court on Monday.
Protesters of all ages chanted in favour of Catalonia's independence from Spain and called for the immediate release of the imprisoned pro-independence leaders.
The massive rally concluded with the president of the pro-independence organization National Assembly of Catalonia (ANC), Elisenda Paluzie, reading out a statement urging Catalan authorities to make another unilateral declaration of independence, as they did in October 2017.
"We urge pro-independence parties to avoid time-delaying maneouvers. If dialogue doesn't arrive, prepare yourselves to support a unilateral independence declaration. We, the people, will be there to peacefully defend it," Paluzie said.
While the main demonstration took place without incident, a parallel protest saw serious disturbances as activists clashed with police, resulting in several injuries and arrests.
Spanish Interior Minister Fernando Grande-Marlaska said in a press conference that 207 officers have been injured so far in the unrest that followed the supreme court's verdict on Monday.
On Friday night, several streets in downtown Barcelona saw police clad in riot gear charge against protesters, leaving a preliminary toll of 89 people injured.
At the iconic Via Laietana street, located near the National Police's headquarters, officers used smoke grenades, tear gas and rubber bullets against groups of youths who had built barricades, started fires and lobbed flare bombs, rocks and glass bottles at them.
It was the fourth consecutive night of unrest in Barcelona since the supreme court's sentences were announced.
Spanish Prime Minister Pedro Sanchez said on Friday that the rule of law "cannot cede to the impulse of exaltation" and warned Catalan premier Joaquim Torra of the dangers of "banalizing" violence.
Meanwhile, Catalan leader Carles Puigdemont, who has been living in self-imposed exile in the Belgian town of Waterloo since fleeing Spanish authorities, is set to appear for a hearing at a Brussels court on October 29 to determine his status.
( With inputs from IANS )