Demonstration against police brutality on October 17, Barcelona Spain. Third day of disturbances because of the sentence condemning the Catalan political prisoners.NurPhoto | NurPhoto | Getty ImagesViolent protests and vandalism have continued in Catalonia for the third night in a row as public anger continues over the sentencing of separatist leaders to long prison terms.Dramatic street battles between protesters and police took place again on Wednesday with barricades and cars set on fire and petrol bombs, as well as reports of acid, being thrown at police.Quim Torra, the president of Catalonia’s regional government in northwest Spain, made a late-night televised statement calling for the violence to stop.”We condemn violence,” he said, according to a translation of the Catalan language provided by Spain’s state broadcaster and reported by Reuters. “We cannot let these incidents happen in our country. This has to stop right now.”Protests erupted in Catalonia, a wealthy region in northwest Spain, after prison sentences totaling almost 100 years were imposed on key leaders of the region’s pro-independence movement.Spain’s Supreme Court on Monday jailed nine Catalan separatist leaders for between nine and 13 years for their involvement in a failed independence bid on October 1, 2017. They were charged with sedition, and some of the leaders were convicted for the misuse of public funds too. Three other prominent figures in the movement were charged with disobedience but were not jailed.Spain’ Interior Minister Fernando Grande-Marlaska said Thursday that Madrid will send more police to Catalonia following the unrest, Reuters reported, saying that this was both to guarantee security and to allow police already there to rest.In further comments on Thursday, Torra said that “the only way to move forward in independence is non-violence.” Acting Prime Minister Pedro Sanchez, who has come under fire for advocating dialogue with separatists, called for “serenity and temperance” Wednesday night.The appearance of extra police in Catalonia could enflame an already tense situation. There are calls from Catalan separatists for a second referendum on independence, despite the first vote in October 2017 being outlawed by the Spanish government and constitutional court.The vote went ahead anyway provoking a constitutional crisis. A recent poll showed that support for independence in the region was outweighed by more people wanting to remain a part of Spain, however.Large scale demonstrations called “Marches for Freedom” are scheduled to take place in Catalonia over the next few days. The marches are setting off from different cities in the region and will converge on Barcelona, the region’s capital Friday.