Veronica Roberts

Chicago, Illinois]--Chicago erupted in violence on Sunday as NATO protesters and police clashed.

As thousands demonstrated in the streets outside the NATO Summit, chanting their displeasure with the wars in Afghanistan and military presence elsewhere, the peaceful crowd suddenly turned into a melee of shoving, screaming with police in full riot mode.

Like a scene out of the Middle East or Greece, police were seen in blue-helmeted riot gear, wielding batons as the protests turned into a full-fledged brawl. The struggle resulted in some getting hurt and bloody protesters could be seen on CNN television being attended by fellow protesters and EMT workers.

Police say a small group of anarchists started throwing sticks and water bottles at them--while taunting and using make-shift weapons, tried to get through the police barricades. Speaking to an ABC reporter about the unrest, Police Superintendent Garry McCarthy said his men had a right to defend themselves.

Police say they were also trying to stop what they called "acts of domestic terrorism" and have already arrested 3 men on Saturday. The 3 were charged with plotting attacks on President Obama" campaign headquarters, as well as the home of Chicago Mayor Rahm Emmanuel. Several financila building were also reported targets. Another suspect, 24 year old Sebastian Senakiewicz to use Molotov Cocktails during the Summit. Police say they have foiled 3 violent plots so far.

The hacker group Anonymous also waged their cyber war, knocking out the police and City's websites. They also called on other hackers to strick Chicago, sayin gin their online video, " should be fired up as much as possible.."

Protesters say the police used excessive force and attacked them without provocation. According to ABC News, up to 50 protesters were arrested and 4 police officers were hurt. One of the injured officers was reportedly stabbed.

The number of protesters who were hurt was not given. Demonstrators say they are taking a stand against the real violence, which is NATO's drone attacks on innocent civilians in Afghanistan, killing even children in the process.

Police say there are anarchists lurking among the protesters and they are hellbent on instigating violence.

NATO, the 28 nation military alliance financed primarily by the U.S., is meeting in Chicago to discuss the war in Afghanistan and other global security. This is the first time the Summit, runing from May 15 to the 22, is held outside of Washington DC.