Protesters clash with Mossos d'Esquadra, the Catalan police force, following a demonstration Saturday in Barcelona against the imprisonment of Spanish rapper Pablo Hasel.

Protesters clash with Mossos d'Esquadra, the Catalan police force, following a demonstration Saturday in Barcelona against the imprisonment of Spanish rapper Pablo Hasel.

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.

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.

About 400 people gathered in the Spanish capitol chanting "Free Pablo Hasél!" while under a heavy police presence, The Guardian reports.