BARCELONA—Ten people were arrested in Barcelona on Saturday for assaulting police officers in fresh unrest over the jailing of a rapper for glorifying terrorism and insulting royalty in his songs. Pablo Hasel, known for his anti-establishment lyrics, was arrested on Feb. 16 after failing to report to serve his sentence, prompting debate over freedom of expression and sparking sometimes violent protests in Barcelona and Madrid. Hasel was convicted for lyrics and tweets that included references to Basque separatist group ETA, calling Spain’s former king Juan Carlos a mafia boss and likening Spanish judges to Nazis. On Saturday evening police in Barcelona chased protesters after they hurled glass bottles, set fire to a police van and smashed the fronts of shops and banks. “Barricades and looting continue in the area of central Barcelona. For safety do not approach this area,” Mossos d’Escuadra, the Catalan regional police, said on Twitter. Some “hooded …