A fifth night of protests in Barcelona over the arrest of a rapper, convicted of criticizing the country's monarchy and glorifying a separatist group, turned violent Saturday with protesters throwing objects at police, setting fires and looting and vandalizing many luxury shops.

Police arrested Pablo Hasél last Tuesday for a 2018 conviction under Spain's Public Security Law, which bans the glorification of terrorist groups and insults against the Spanish monarchy. Authorities cite politically inflammatory lyrics and social media posts for charging Hasél, but his arrest immediately set off days of protests and sparked a debate over freedom of expression.

Thousands took to the streets Saturday night, protesting Hasél's conviction and nine-month sentence. At one point, demonstrators hurled projectiles and flares at police, who fired foam bullets to break up the crowds.

Shops on the city's tony shopping district, Passeig de Gràcia, were looted and vandalized. Videos and photos from the night show smashed windows along the avenue and groups running through at least one boutique, swiping items off racks.

Windows of the city's Palau de la Música concert hall were also smashed, Reuters reports, citing a local newspaper. Video and images show objects set ablaze.

Police say barricades and motorcycles were also set ablaze.

At least 31 people were arrested in Barcelona on charges of looting and public disorder, Catalan Regional Police said on Twitter. Two others were also arrested in the city of Tarragona and one in Lleida, police said.

Nine people were also injured, Reuters reports, with two of them taken to a hospital.

Reuters further reports that a demonstration in Madrid remained peaceful. About 400 people gathered in the Spanish capitol chanting "Free Pablo Hasél!" while under a heavy police presence, The Guardian reports.

Reuters notes that police charged toward protesters in the city of Pamplona.

Violence has broken out throughout the demonstrations that were sparked by Hasél's arrest last Tuesday. Riot police had reportedly stormed a Lleida University building were Hasél and supporters had barricaded themselves, after Hasél missed a deadline to turn himself in.

Earlier on Saturday, Cristina Narbona, president of the country's Socialist Party, condemned the violence that had erupted over the previous four nights of protests.

"We reiterate our strongest condemnation of violence which cannot be justified as a defense of the freedom of expression," Narbona said, according to Reuters.

Scores of people have been arrested across the region since protests began. A woman reportedly also lost an eye during clashes in Barcelona, prompting several politicians to call for an investigation into police tactics.

Calls for Hasél's release have grown to include prominent Spanish artists and celebrities. Film director Pedro Almodóvar and actor Javier Bardem have signed a petition for his release.

Amnesty International has also defended Hasél, whose online statements have, authorities allege, criticized Spanish royalty and shown support for the ETA, which waged a bloody decades-long campaign for independence. The Basque separatist group officially disbanded in 2018.

Supporters of Hasél have described the 2015 security law as a "gag" rule that has limited his freedom of expression. Spain's Justice Ministry has recently announced plans to reform the law to target only actions that encourage violence, though it is unclear what effect this could have on Hasél's case.

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