BARCELONA, Spain (AP) — A fifth night of peaceful protests to denounce the imprisonment of a Spanish rap artist once more devolved into clashes between police and the members of fringe groups who set up street barricades and smashed storefront windows Saturday night in downtown Barcelona.

Small groups made up mostly of young people began their nightly cat-and-mouse game with officers an hour after several thousand protesters gathered in the capital of Spain’s Catalonia region, which also was where the worst violence took place during earlier demonstrations this week.

On Saturday, rioters looted stores on Barcelona’s main shopping street and then threw stones after police in riot gear poured out of vans to engage them.

Hundreds also gathered in Madrid, and hundreds more marched the northeast town of Lleida, where rapper Pablo Hasél was arrested on Tuesday and taken away to begin serving a nine-month prison sentence for insulting the Spanish monarchy and praising terrorist violence in his music.

Around 80 people have been arrested, including four on Friday night, and more than 100 people injured since Hasél arrested by police on Tuesday.

The disorder appears to have come from a fringe group of mainly younger people who constituted a small share of the thousands of participants who joined in marches to support Hasél and to oppose the Spanish laws used to prosecute him.

Police in Catalonia, the region surrounding Barcelona, have reported at least three mob attacks on police stations. Rioters smashed their way into bank offices in downtown Barcelona, burned trash containers, and looted sporting goods stores on Friday night.

Barcelona Mayor Ada Colau made an appeal for calm.

“Defending the freedom of expression doesn’t justify in any case the destruction of property, frightening our fellow citizens, and hurting businesses already hurt by the crisis” caused by the pandemic, the mayor said.

Madrid municipal authorities said that 300 National Police officers were called up to assist city police.