Streets in Barcelona were ablaze on Friday night as hundreds of protesters battled with police in the heart of Spain's most visited city.
Fiery barricades were set up and rocks hurled at security forces.
It was the fifth day of unrest following the jailing of Catalan separatist leaders.
Masked youths blocked a road close to the city's police headquarters.
They set fire to large garbage bins and threw stones, cans and bottles towards security forces.
Police responded with repeated volleys of foam bullets, smoke grenades and tear gas.
It followed a day of largely peaceful demonstrations in the Catalan capital.
Officials said there were clashes in at least four other towns and cities in Spain's wealthiest region in the far northeast of the country.
Spain's interior ministry said 207 police had been injured since Monday and 128 people have been arrested in the region over the past five days
As pro-independence anger shows no sign of abating.