More than 50 people were arrested and dozens injured during a second night of violent protests in several Spanish cities.

The demonstrations were sparked by the imprisonment of rapper Pablo Hasel who had insulted the monarchy and praised terrorism.

The protests began peacefully late on Wednesday in dozens of Spanish provincial capitals and other towns in the northeastern Catalonia region.

But as the evening wore on they turned violent, with rioting, impromptu barricades made from bins and fires, and damage to shops.

In Madrid, Barcelona and smaller cities, anti-riot police fired rubber or foam bullets at baton-charged protesters, who threw objects at officers and set bins alight. Some used overturned motorbikes to block streets.

In the Spanish capital alone, police arrested 19 people, including six youngsters.

Emergency services assisted 35 injured anti-riot officers and 20 others, including protesters and people who were passing by and got caught in the melee.

In Barcelona, 29 people were arrested and at least eight were injured and sent to hospitals, the regional emergency service said on Thursday.

At least four protesters were also arrested on Wednesday in the southern city of Granada.

Some of the most serious riots on Wednesday night took place near the Lleida prison, where Hasel was taken on Tuesday.

Police arrested him at a university building where he had barricaded himself in 24 hours earlier to draw attention to his arrest.

The rapper and his supporters say that Hasel’s nine-month sentence for writing a critical song about former King Juan Carlos I and dozens of tweets that judges said glorified some of Spain’s extinct terrorist groups violates free speech rights.

Before that case, the rapper had been given a suspended two-year sentence and faced other charges for assault, praising armed extremist groups, breaking into private premises and insulting the monarchy.

His legal situation has drawn considerable public attention because it comes on the back of a string of other artists and social media personalities having been put on trial for violating Spain’s 2015 Public Security Law, which was enacted by a previous conservative-led government and criticised by human rights organisations.

Spain’s left-wing coalition government wants to change the country’s criminal code to eliminate prison terms for offences involving freedom of speech, especially when it comes in the form of artistic expression.