BARCELONA—Catalonia’s secessionist leader Thursday pledged another referendum on independence from Spain, after days of clashes between police and protesters left hundreds of people injured.
Thousands of protesters have taken to the streets since Spain’s highest court on Monday sentenced nine Catalan pro-independence leaders to between nine and 13 years in jail over their roles in an illegal referendum in 2017.
The verdict has revived tensions surrounding the long-held hopes by many Catalans for independence from the rest of Spain. Those aspirations culminated in the 2017 referendum, after which separatist lawmakers declared the region’s independence. That move prompted Madrid to take control over the region.
Separatists have planned a general strike for Friday to protest the verdict and renew their call for an independence vote.
“If we have been condemned to 100 years in prison for putting out ballot boxes, the response is clear: We’ll need to put the ballot boxes out again for self-determination,” Catalonia’s regional leader, Quim Torra, told lawmakers.
Thursday marked the fourth night of protests. Several boulevards were shut to traffic and police vans were parked throughout the center of Barcelona, the regional capital. Helicopters flew overhead. Many taking part expected more protests to follow.
Xavier Trilla, a 40-year-old Barcelona resident, said he would welcome another independence vote if citizens were really free to cast their ballot.
“What would be amazing, really, would be a normal referendum without police so that we could find out what people really want,” said Mr. Trilla.
Episodes of violence and vandalism have become more common in the lead-up the general strike.
Riot police and protesters clashed on Wednesday night. Dozens of trash cans and cars were set on fire, and police said protesters threw rocks as well as acid at them. Fireworks targeted a police helicopter without causing significant damage.
At least 350 people have been injured, including over a hundred members of the regional police force, according to authorities, who said 72 people have been detained. The regional government and separatist leaders have condemned the violence, blaming it on infiltrators.
The protests have placed the issue of Catalan secession once again at the heart of Spain’s political debate as the country prepares to vote in parliamentary elections next month.
The vote pits acting Prime Minister Pedro Mr. Sánchez’s incumbent Socialists, who espouse a conciliatory approach to Catalonia, against center-right opposition parties and far-right Spanish nationalists who have been calling for a tougher stance.
Mr. Sánchez’s hopes to reduce Catalan demands for secession through dialogue and potentially greater autonomy for the wealthy region, which already manages its own education and health-care system. But growing tensions between the regional government and Madrid are testing this approach.
“The state will always uphold the rights of those who demonstrate peacefully. But it will not tolerate the imposition of violence,” he said Wednesday.
Write to Margherita Stancati at margherita.stancati@wsj.com and Pietro Lombardi at Pietro.Lombardi@dowjones.com
