Protesters rallied outside the Chicago campaign headquarters of President Barack Obama on Monday on the last day of the two-day NATO summit . The peaceful nature of the demonstration came in stark contrast to violent clashes that left protesters and eight police officers injured a day before . `` NATO has to go . Everywhere they go , this is the result -- violence against innocents , violence in the service of the international 1 % , '' said Joe Iosbaker , an activist . `` We are here to demand accountability , and we 're not just talking about the rank and file cops who did the swinging and split skulls . We 're talking about ( Chicago ) Mayor ( Rahm ) Emanuel and ( Chicago ) Police Superintendent ( Garry ) McCarthy , '' he said . Earlier in the day , protesters chanted and tossed paper airplanes as they protested Boeing Corp. 's role as a defense contractor . `` These are peaceful protesters . That 's what we expected , '' said superintendent McCarthy . Later in the day , he drew a distinction between protesters and criminals . `` Yesterday was not a clash between protesters and police . That was a clash between criminals and police , '' he told CNN . `` The news is n't what happened . The news is what did not happen . '' By early afternoon , protesters had moved on from the heavily guarded Boeing building , where some windows had been covered in anticipation of possible violence . `` It 's kind of a celebration , '' protester Blaise Sewell said . `` We effectively shut down Boeing with a Facebook event . '' While McCarthy said officers behaved admirably in the face of attacks by protesters Sunday , the Chicago chapter of the National Lawyers Guild accused police , in a statement , of `` indiscriminate violence . '' `` Police completely overreacted to protesters approaching the security perimeter and unleashed a violent attack on them without an ability to disperse , '' attorney Sarah Gelsomino of the People 's Law Office said in the guild statement . Protesters suffered serious injuries , including broken bones , busted lips and concussions , she said at a Monday rally . The guild has close to 60 accounts of police brutality , Gelsomino said . Security remained tight in Chicago as the summit wound down . Commuters faced a more difficult trip with the closure of 25 stops on the city 's Metra train lines , which had been planned earlier . The city 's iconic Lake Shore Drive was also to remain closed through much of downtown , city officials said . Speaking inside the the NATO meeting , President Barack Obama thanked the people of Chicago for putting up with the traffic and also the city 's mayor and its police force for their work , which he said was done under `` some significant pressure and a lot of scrutiny . '' `` This is part of what NATO defends -- is free speech and freedom of assembly , '' he said . A day earlier , police clashed with protesters at the end of a march just blocks from the NATO summit after a they refused police orders to disperse and began pushing against a line of officers clad in riot gear . A video from CNN affiliate WLS showed protesters , some with bloodied faces , struggling against the officers , some of whom struck the demonstrators with batons . The confrontation led to a two-hour standoff between police and protesters . Occupy Chicago said dozens were injured in the clashes , though fewer than a dozen protesters were treated at area hospitals , officials said . McCarthy said Monday that eight officers had been injured , including one who was hospitalized for exhaustion and another who was stabbed in the leg but went back on duty hours later . Police said they arrested at least 45 people Sunday . The National Lawyers Guild estimated 60 arrests Sunday and more than 100 since the summit began . On Sunday , McCarthy said officers responded after protesters assaulted them , and `` the finger should be pointed at the people who assaulted the cops . '' On Monday , he said protesters were largely peaceful and blamed Sunday 's violence on a group of protesters intent on breaking the law . While police want to protect people exercising free speech rights , he said , they can not tolerate illegal acts . Police spokeswoman Melissa Stratton also said Monday that some protesters had splashed themselves with fake blood before returning to the protest lines . While some protesters accused police of brutality in Sunday 's confrontations , Illinois Lt. Gov . Sheila Simon said Monday that police seemed to be doing a good job . `` I think for the most part , they have been doing a fantastic job of making sure that people are protected and free speech rights are protected as well , '' she said . `` It 's a tough balance to get , but I think they are doing a good job . ''
Police superintendent draws a distinction between protesters and criminals . Obama says police did a `` great job under some significant pressure '' Protesters rally outside the Chicago campaign headquarters of Obama . Dozens were injured in clashes between police and protesters Sunday .