More than 20 people were injured as police used riot batons to keep protesters away from federal buildings in Barcelona on Friday night.
Demonstrations also took place in other parts of Catalonia.
Spain's Supreme Court ruled 25 Catalan leaders should be tried for rebellion, embezzlement or disobeying the state. Convictions could result in up to 30 years in prison.
In Madrid, a Supreme Court judge ordered five more Catalan leaders to be detained without bail, pending trial over their involvement in October's banned independence referendum.
One of those taken into custody was Jordi Turull who was to be the subject of a vote in the Catalan parliament on Saturday for regional president.