(CHICAGO) -- Protesters clashed with police at the end of what had been a peaceful march and rally by thousands of demonstrators, led by disenchanted veterans of the Iraq and Afghan wars protesting the opening of the two-day NATO summit in Chicago on Sunday.
The battle between protesters believed to be members of the anarchist group Black Bloc and police left several demonstrators bloodied, and marred what had been a solemn and orderly march.
At the end of the march, the vets threw their NATO medals over the fence set up by the Secret Service around McCormick Place.
The demonstrators had a wide range of agendas; there were anti-war activists, people concerned about inaction on climate change, and people protesting the handling of the global economy.
But the activists on the street weren't the only ones aiming to disrupt the summit. A hacking group affiliated with Anonymous took responsibility for temporarily crippling the Chicago Police and NATO websites Sunday.
Chicago police are working with federal authorities to investigate the attack and the extent of it, the Chicago Tribune reported.
NATO has not confirmed it was the victim of a cyber attack.
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