Thousands of protesters took to Chicago's streets ahead of the NATO summit due to kick off there on Sunday. National Nurses United teamed up with trade unions and the Occupy movement to form a mass rally in the Windy City.

­The NNU members demanded a Robin Hood tax to be introduced on banks' financial transactions. That demand was rather a supplement to the protest against proposals to cut back nurses pensions.

"We've worked 30 years for them and don't want to get rid of them," said Deb Holmes, a nurse at a hospital in Worcester.

Former Rage Against the Machine guitarist and Occupy activist Tom Morello performed live at the event.

Despite the largely peaceful nature of the event, one man was arrested for aggravated battery of a police officer.

While marching through the streets a group of several hundred protesters split up from the main rally and rushed through the city shouting all kinds of anti-NATO slogans and making caustic remarks to police officers. Over a dozen of these activists were arrested.

The Friday March has merely been a rehearsal for a really big rally scheduled for Sunday, when the NATO summit opens. The thousands of protesters that continue to arrive in Chicago have put the city in security overkill mode.

NATO in crosshairs of fierce criticism

­The hometown of the ruling US President Barack Obama plays host to this year's NATO summit and the event has turned city police paranoid over security matters in already the most-watched city in the US.

© Scott Olson / Getty Images / AFP
Thousands of nurses led the way Friday with a march through Chicago, demanding investment in public healthcare instead of Obama's war machine
"We've got a bunch of peaceful protesters here, and they [police] spent millions and millions of dollars on this week alone. It's absolutely absurd," told RT Sam Molik, protester from Occupy Tulsa.

Chicago authorities have spent millions of dollars on new police gear.

NATO critics flocking to the city to stage mass protests make no secret of their negative attitude towards the alliance. Demonstrators want the money pumped into the summit and its security to be spent on real needs.

RT's Anastasia Churkina interviewed people on the city's streets and their remarks about NATO have been overwhelmed by bitter resentment.

"NATO is a US-commanded military alliance responsible for wars and war crimes on a global basis," one woman told RT.

"NATO as an organization no longer has a mandate. Occupy Chicago denies and demands NATO disband. They have no more purpose. They are spending our taxpayer dollars on wars and to bomb and destroy and murder civilians all over the world," accuses Occupy Chicago press committee member Micah Philbrook.

"There is a pro-peace majority in the United States. We oppose war. We oppose the world's pre-eminent work-making organization NATO. And we have a human agenda and a humane agenda that has no place for war,"political analyst and writer Rick Rozoff told RT.