Emergency services said Wednesday that 33 people were treated for injuries in the disturbances.
Among the targets of the rapper's controversial tweets were the police, which he described as "mercenaries of s***," and the monarchy.
Sunday's elections in Spain's Catalonia region gave separatists a boost in the regional parliament.
Separatist parties have boosted their majority in Catalonia’s parliament, although the pro-union Socialist Party claimed a narrow win in elections held amid a third wave of coronavirus.
The long-standing demands for self-determination by Catalan separatists, the handling of the pandemic and its economic fallout are the main issues being debated during the run-up to the vote.
Two men stand accused of belonging to the jihadist cell that orchestrated the attacks in the Barcelona area in August 2017, while the third defendant is accused of collaborating.
Supporters of Catalonia's secession from the rest of Spain gathered in small groups around the north east region on Friday under orders from event organisers to maintain social distancing amid a spike in coronavirus cases.
An estimated 50,000 pro-independence protesters attended the main demonstration in Barcelona to mark the Catalan National Day. It was a muted affair compared to previous years because of local coronavirus restrictions.