By Luis Felipe Castilleja and Guillermo Martinez
MADRID/BARCELONA (Reuters) - Police fired tear gas, rubber bullets, and sound bombs at two protests in Madrid and Barcelona on Wednesday, each attended by thousands, the day after a rapper was arrested on charges of glorifying terrorism and insulting royalty in his songs.
Protests in the capital's central Plaza de Sol square were initially peaceful, with people clapping their hands in unison and chanting "No more police violence" and "Freedom for Pablo Hasel", the rapper detained in the Catalan city of Lleida on Tuesday.
But police charged into the crowd wielding batons after a few protesters began throwing glass bottles and stones they had loosened from the pavement. Some protesters responded by setting fire to containers to create barricades in the narrow Madrid streets.
In Catalonia's Barcelona, there were similar scenes as local police the Mossos d'Esquadra fired rubber bullets into the crowd on Wednesday, injuring a Reuters reporter on the ground.
When Catalan protesters began throwing projectiles at the armoured vans, the Mossos retaliated by shooting rubber bullets aimed at face-level. As the riots appeared to stagnate, large stretches of central Barcelona streets were choked with smoke from burning bins.
Pablo Hasel, known for his radical leftist views, had missed a deadline last Friday to surrender to authorities to serve a nine-month jail term handed down in 2018 - a sentence that caused an uproar in Spain and led the government to announce it would make free speech laws less restrictive.
On Tuesday, police had stormed a university building where Hasel had barricaded himself and arrested him, triggering rallies and riots in Barcelona and other Catalan cities.
Police arrested 18 people, while 55 were injured, including 25 officers, officials said on Tuesday.
Protest organisers used social media to call for further rallies on Wednesday night to demand Hasel's release across Spain, including in Madrid.
A source at Catalonia's interior department said police had "strengthened sensitive areas" to avoid more riots, but declined to give further details.
During a news briefing, regional security chief Miquel Samper appealed to protesters to congregate peacefully.
A police source said there was no plan to bolster security nationwide for the protests, however.
(Reporting by Silvio Castellanos, Guillermo Martinez in Madrid, and Jordi Rubio, Luis Felipe Castilleja, Albert Gea and Joan Faus in Barcelona; additional reporting by Emma Pinedo; writing by Clara-Laeila Laudette; editing by Andrei Khalip and Jonathan Oatis)