Yesterday, as thousands marched through Chicago in protest of the NATO military summit, police and protesters clashed, with some people claiming extreme police brutality.

The clashes occurred as the demonstrators were trying to push their way through a police line to the site of the NATO summit. Protesters allegedly threw plastic bottles and paint balloons, at this point police are said to have used batons against them . At least 12 people were injured including journalists covering the march. Images show people with bloodied faces, following the clashes.

Police estimated that around 2-3,000 people took part in the demonstration, however photos suggest it was many more. Protests had also taken place on Friday and Saturday, but yesterday was by far the biggest.

Iraq and Afghanistan veterans also took part in the march, pictures show some of them throwing their medals towards the center where the delegates were meeting. They said the medals they were given do not represent the wars they were fighting. Many of the other protesters were affiliated with the Occupy movement, who have been protesting since October last year against income inequality in the US.

As well as injured protesters, four Chicago police officers were also hurt. Superintendent Garry McCarthy has confirmed that one officer suffered a stab wound to the leg, and three others were injured during the clashes yesterday. Despite the allegations of police brutality from protesters, McCarthy commended his officers for showing "dramatic restraint" in the face of taunts and violence from protesters.

Approximately 60 people were arrested yesterday, but despite this protest organisers have said that they expect their numbers to swell in the next few days as the demonstrations continue.

[Photographs via @OccupyChicago and @YourAnonNews]