Toronto , Ontario ( CNN ) -- Police fired tear gas outside a prisoner processing center Sunday in Toronto where groups of people gathered to protest the arrest of G-20 demonstrators , a security spokeswoman said . A total of 604 people have been arrested since the protests broke out June 18 , said Constable Tim Garland of the Ontario Provincial Police . At least 253 of those arrests came on Sunday , he said . Canadian Prime Minister Stephen Harper had harsh words for demonstrators who set at least four police cars ablaze and shattered several windows around the city during the weekend 's protests . `` We obviously deplore the actions of a few thugs , '' Harper said at the conclusion of the G-20 summit . Some of the detained protesters were released Sunday from the prisoner processing center -- an old film studio converted to a makeshift jail amid the protests -- while others were being held for bail , Ontario Provincial Police Constable Rodney Petroski said . Some of those released emerged in their stocking feet , carrying a bag of their belongings and speaking about the conditions inside the center . Several detainees who had been arrested for `` breach of peace '' told CNN that they were n't given access to legal counsel and were denied blankets and frequent trips to the bathroom outside what they described as 6-foot by 9-foot makeshift cells . Elsewhere , mobs scuffled with police in multiple locations , according to Neda Snyder , a spokeswoman for the Integrated Security Unit . Of the Sunday arrests , 70 took place on one thoroughfare , Bancroft Avenue , she said . There were no reports of serious injuries to either protesters or police , according to the ISU , which said the safety of summit participants was never compromised . `` I do not believe that the individuals bent on vandalism and violence in our city have finished with their intent , so we will remain vigilant , '' Toronto Police Chief Bill Blair said Saturday night . Blair told reporters that packs of disruptive demonstrators infiltrated peaceful protests in order to cause chaos and distract police . `` These criminals rely on the anonymity of hiding in a larger group of the curious and the naive , '' he said . At least four police cars went up in flames and smoke during hours of confrontation , authorities said . Protesters left behind broken windows and graffiti . Blair said police used tear gas after warning a group of protesters `` engaged in acts of destruction '' Saturday . Not all encounters between police and protesters were hostile . At one intersection the crowd danced and chanted , `` You 're sexy , you 're cute , take off your riot suit ! '' More aggressive groups of demonstrators moved from intersection to intersection , trying to circumvent police and get to the security fence protecting the summit meeting . `` The fence is a symbol that they can build a fence and spend a billion dollars on their agenda . The fence is a symbol of what 's wrong with this country , '' protester Rolf Gerstenberger said . Authorities said the fence was not breached Saturday . Behind it , world leaders met for an economic summit focusing on recovery from the global financial crisis . Participants agreed on ambitious targets for getting deficits under control , pledging to cut them in half by 2013 , according to a final statement made at the conclusion of the conference . This weekend 's meetings come on the heels of the two-day G8 summit outside Toronto , where the leaders of the United States , Canada , France , Germany , Britain , Italy , Japan and Russia also focused on recovery from the global economic crisis . The group also made note of other thorny issues in their final statement issued Saturday , singling out Iran and North Korea for criticism . CNN 's Jeanne Meserve , Ali Velshi , Rachel Streitfeld and Leslie Perrot contributed to this report .
NEW : At least 253 people protested peacefully . NEW : Canadian PM : We suspect group of thugs . Protests erupt in Toronto as G-20 leaders meet . Police have arrested more than 600 protesters since mid - June .