BARCELONA, Spain (AP) — Three straight days of clashes between protesters and police in Catalonia won't provoke authorities into taking drastic measures, Spain's caretaker prime minister Pedro Sánchez said Wednesday, as new riots rocked Barcelona.

The Spanish government will respond with "firmness, calmness and unity" to the violence, Sánchez said in a televised address.

As he spoke in Madrid, tens of thousands of protesters faced off against riot police in Barcelona, with some protesters setting up flaming barricades in the streets, torching cars and throwing stones, bottles and firecrackers at police.

Police also reported clashes in Girona, a town near the French border.

Violence first erupted in Catalonia after Spain's Supreme Court on Monday handed nine separatist Catalan leaders lengthy prison sentences for their part in an October 2017 effort to achieve independence.

The clashes have injured more than 200 people, including police, over the past three days. Police made 29 arrests on Tuesday.

Many people in Catalonia have long fought for it to break away from Spain and become a new European country. Demonstrations have traditionally been peaceful, but not always.

Protests on Wednesday followed the pattern of previous days as crowds gathered during the day to block roads and hold marches demanding independence. After sunset, marches turned ugly.

In downtown Barcelona, protesters threw hundreds of white paper toilet rolls into the air to show their anger over the prison sentences. Organizers said the toilet rolls were thrown because "there is a lot that needs cleaning up."

Sánchez blamed "organized groups of extremists" for the rioting but said he wouldn't be drawn into playing their game of an 'ascending spiral of violence."

Sánchez consulted with other national political leaders in Madrid during the day about the trouble in Catalonia.

With a general election due on Nov. 10, some of Sánchez's political rivals publicly urged him to take a firmer hand, adopting exceptional measures in the restive region.

An organization representing downtown Barcelona businesses, called Barcelona Abierta, said the violence in the city had caused "significant losses" and "deeply damaged" the image abroad of the popular tourist destination.

Pere Ferrer, director of Catalonia's regional police, said the street violence was "intolerable."

"The situation is very, very difficult, but the police have the means they need to deal with it," he told a Barcelona news conference.

Thousands of people joined five large protest marches across Catalonia that converged in central Barcelona Friday.

They included families with children, elderly and young people, and banners reading "Libertat Presos Politics" (Freedom for political prisoners) — a reference to the prominent Catalan politicians and activist leaders sentenced by the Supreme Court.

Other protests are scheduled in coming days as separatists vowed no let-up in their independence drive.

Feliu, a retiree who walked 20 kilometers (12 miles) from the northern town of Berga and asked to be identified only by his first name because of the delicate situation in Catalonia, said he didn't agree with the violence but saw it as a way of gaining attention.

"If foreigners see us protesting peacefully all the time, they might think that nothing is going on or they might not even notice us," the 68-year-old said.

The imprisoned separatist leaders have grown into powerful symbols and a rallying point for the separatist movement.

Catalan regional president Quim Torra joined one of the marches, saying he wanted to be next to the people.

"These peaceful marches happening across the country (Catalonia) are the Catalan people's best response" to the court's verdict, Torra said.

Torra, one of the separatist movement's leaders, didn't criticize the recent street violence.

Roughly half of the region's 7.5 million residents support independence, with the other half opposing a breakaway, according to polls.

Students in the restive region went on strike, with organizers urging them to remain peaceful.

Gabriel Rufián, a leading Catalan separatist and member of Spain's parliament, and some other high-profile secessionists, called for calm.

"Nothing can justify violence," Rufián told Cadena SER radio.

Most impromptu protesters have responded to an online campaign by Tsunami Democratic, a shadowy grassroots group that uses encrypted messaging apps to call for peaceful disobedience.

Spanish Interior Minister Fernando Grande-Marlaska said authorities were investigating the group.

But on Wednesday, the group issued a statement appealing for an end to the violence.

The Supreme Court found nine of 12 Catalan politicians and activists guilty of sedition and gave them prison sentences of nine to 13 years. Four of them were additionally convicted of misuse of public funds. The other three were fined for disobeying court orders.

___

Aritz Parra in Madrid, Bernat Armangue in Navas, and Barry Hatton in Lisbon, Portugal, contributed to this report.