Veterans who have served in Iraq and Afghanistan returned their service medals to visiting NATO representatives Sunday to express their opposition to America's role in these conflicts, and to demand better care for returning forces.

Members of Iraq Veterans Against the War organized a day-long protest, including a musical performance at the Petrillo Music Shell, a march and rally through the city and a ceremony at Michigan and Cermak where participants hoped to return their medals to visiting NATO generals.

(Scroll down to watch interviews with the veterans from "Democracy Now!")

While Rev. Jesse Jackson and other political leaders spoke to demonstrators before they began a massive march through downtown Chicago, the group was unable to bring visiting NATO generals to accept their medals, so the 45 participating veterans hurled them at McCormick Place, where NATO meetings were taking place, according to ABC.

The veterans joined forces with their former enemies, including the group Afghans for Peace, who said their missions are closely aligned--to end

"I'd like to direct my message to the NATO representatives here in Chicago today," said Suraia Sahar of Afghans for Peace, according to MSNBC. "For what you’ve done to my home country, I’m enraged; for what you’ve done to my people, I’m disgusted; for what you’ve done to these veterans, I’m heartbroken. I sympathize with their disappointment and being failed by the system and having their lives, their morals and humanity, toiled with."

IVAW organizer and veteran Aaron Hughes, who pulled out of the University of Illinois in 2003 to serve in Kuwait under Operation Iraqi Freedom, says one of the group's main concerns is the need for adequate mental health care for returning servicemen and women, according to NBC Chicago.

On average, 18 veterans commit suicide every day, and Post Traumatic Stress Disorder is rampant among veterans who've seen combat, according to CBS Chicago.

The peaceful demonstration organized by IVAW was soon overshadowed as violence broke out during a standoff between police and protesters Sunday evening, resulting in 45 arrests and four police officers suffering injuries –- one from a stab wound in the leg.

WATCH veterans discuss their decisions to toss their service medals Sunday:

Also on HuffPost:

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  • Alex Kennedy, left, from Geneva, Ill., and Dillon Roberts, from Bartlett, Ill., kiss after a demonstration and march to President Barack Obama's campaign headquarters in Chicago on Monday, May 21, 2012, the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

  • A Chicago police officer videotapes a verbal lashing from a protester outside the President Barack Obama's campaign headquarters in Chicago, Monday, May 21, 2012, on the final day of the NATO summit. (AP Photo/Robert Ray)

  • Protesters march to Boeing corporate offices for a demonstration as a part of the NATO summit Monday, May 21, 2012 in Chicago. Demonstrators prepared Monday to launch another round of protests in the final hours of the NATO summit, a suburban community that could become the site of a detention facility to hold illegal immigrants. (AP Photo/Nam Y. Huh)

  • Protesters sit on Michigan Avenue and give the peace sign during a march to President Barack Obama's campaign headquarters in Chicago on Monday, May 21, 2012, the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

  • A protester signals during a march to Boeing corporate offices for a demonstration as a part of the NATO summit Monday, May 21, 2012 in Chicago. Demonstrators prepared Monday to launch another round of protests in the final hours of the NATO summit, a suburban community that could become the site of a detention facility to hold illegal immigrants. (AP Photo/Nam Y. Huh)

  • A protester wearing mask of Chicago Mayor Rahm Emanuel, shoots out silly string during a demonstration outside Boeing corporate offices Monday, May 21 2012, in Chicago, on the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

  • Protesters shoot silly strings and blow bubbles while demonstrating in front of Boeing corporate offices as a part of the NATO summit Monday, May 21, 2012 in Chicago. (AP Photo/Nam Y. Huh)

  • Protesters demonstrate outside Boeing's corporate offices Monday, May 21 2012, in Chicago, on the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

  • Barack Obama,

  • Barack Obama,

    President Barack Obama walks off stage at the end of his news conference at the closing of the NATO Summit in Chicago, Monday, May 21, 2012. (AP Photo/Pablo Martinez Monsivais)

  • Barack Obama

    President Barack Obama speaks at a news conference at the NATO Summit in Chicago, Monday, May 21, 2012. (AP Photo/Kiichiro Sato)

  • Barack Obama

    President Barack Obama speaks at a news conference at the NATO Summit in Chicago, Monday, May 21, 2012. (AP Photo/Kiichiro Sato)

  • Barack Obama

    President Barack Obama speaks at a news conference at the NATO Summit in Chicago, Monday, May 21, 2012. (AP Photo/Kiichiro Sato)

  • Barack Obama

    President Barack Obama arrives at a news conference at the NATO Summit in Chicago, Monday, May 21, 2012. (AP Photo/Kiichiro Sato)

  • Barack Obama,

    President Barack Obama smiles during his news conference at the NATO Summit in Chicago, Monday, May 21, 2012. (AP Photo/Pablo Martinez Monsivais)

  • Kim Sung-hwan

    South Korean Foreign Minister Kim Sung-hwan, right, talks with others attending the NATO Partners meeting during the NATO Summit, Monday, May 21, 2012, in Chicago. (AP Photo/Carolyn Kaster)

  • Barack Obama, Dalia Grybauskaite

    President Barack Obama arrives for the NATO Partners meeting during the NATO Summit, Monday, May 21, 2012, in Chicago. At left is Lithuanian President Dalia Grybauskaite. (AP Photo/Carolyn Kaster)

  • Protesters chant during a demonstration in front of Boeing corporate offices as a part of the NATO summit Monday, May 21, 2012 in Chicago. (AP Photo/Nam Y. Huh)

  • Chicago Police Superintendent Garry McCarthy address the news media during a protest march to Boeing corporate offices for a demonstration as a part of the NATO summit Monday, May 21, 2012 in Chicago. (AP Photo/Nam Y. Huh)

  • The NATO leaders gather for a group picture upon their arrival for dinner at Soldier Field in Chicago, Sunday, May 20, 2012. Front row from left are Canadian Prime Minister Stephen Harper, Bulgarian President Rosen Plevneliev, Belgium Prime Minister Elio Di Rupo, Albanian Prime Minister Sali Berisha, President Barack Obama, NATO Secretary General Anders Fogh Rasmussen, British Prime Minister David Cameron, Turkish President Abdullah Gul, Spanish Prime Minister Mariano Rajoy and Slovenian Prime Minister Janez Jansa. Second row from left are Croatian President Ivo Josipovic, Czech Republic President Vaclav Klaus, Danish Prime Minister Helle Thorning-Schmidt, Estonian President Toomas Hendrik Ilves, French President Francois Hollande, German Chancellor Angela Merkel, Greek Foreign Minister Petros Molyviatis, Hungarian Prime Minister Viktor Orban, Iceland's Prime Minister Johanna Siguroardottir, and Italian Prime Minister Mario Monti. Back row from left are Luxembourg Prime Minister Jean-Claude Juncker, Lithuanian President Dalia Grybauskaite, Portuguese Prime Minister Pedro Passos Coelho, Latvian President Andris Berzins, Netherlands Prime Minister Mark Rutte, Romanian President Traian Basescu, Norwegian Prime Minister Jens Stoltenberg, Polish President Bronislaw Komorowski, and Slovakian President Ivan Gasparovic. (AP Photo/Carolyn Kaster)

  • NATO Secretary General Anders Fogh Rasmu

    NATO Secretary General Anders Fogh Rasmussen speaks during a press conference in Chicago during the NATO 2012 Summit on May 21, 2012. AFP PHOTO/Jim WATSON (Photo credit should read JIM WATSON/AFP/GettyImages)

  • Hillary Rodham Clinton, Alexander Vershbow

    Secretary of State Hillary Rodham Clinton, accompanied by NATO Deputy Secretary General Alexander Vershbow, speaks at a meeting of the NATO Foreign Ministers during the NATO Summit, Monday, May 21, 2012, in Chicago. (AP Photo/M. Spencer Green)

  • Barack Obama, Anders Fogh Rasmussen, Mikhail Saakashvili, David Cameron,

    President Barack Obama takes his seat with NATO Secretary General Anders Fogh Rasmussen, right, at the Partners Meeting at the NATO Summit in Chicago, Monday, May 21, 2012. At left is British Prime Minister David Cameron talking to Georgian President Mikhail Saakashvili. (AP Photo/Pablo Martinez Monsivais)

  • Valerie Trierweiler

    French First Lady Valerie Trierweiler is welcome by pupils as she arrives to visit a French school in Chicago, Monday, May 21, 2012. (AP Photo/Eric Feferberg, Pool)

  • Protesters demonstrate in front of Boeing corporate offices as a part of the NATO summit Monday, May 21, 2012 in Chicago. (AP Photo/Nam Y. Huh)

  • Protesters fly paper airplanes during a demonstration outside Boeing corporate offices Monday, May 21 2012, in Chicago, on the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

  • Protesters participate in a "die-in" as part of a demonstration outside Boeing's headquarters Monday, May 21 2012, in Chicago, on the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

  • Protesters stage a die-in

    Protesters stage a die-in in front of Boeing corporate offices as a part of the NATO summit, Monday, May 21, 2012 in Chicago. (AP Photo/Robert Graves)

  • Protesters gather at Union Park, in Chicago before marching to Boeing for a demonstration as a part of the NATO summit Monday, May 21, 2012 in Chicago. Demonstrators prepared Monday to launch another round of protests in the final hours of the NATO summit, a suburban community that could become the site of a detention facility to hold illegal immigrants. (AP Photo/Nam Y. Huh)

  • A protester uses her phone during a die-in at Boeing

    A protester uses her phone during a die-in at Boeing corporate offices as a part of the NATO summit Monday, May 21, 2012 in Chicago. (AP Photo/Nam Y. Huh)

  • A protester stands before Chicago Police at the Art Institute where First Lady Michelle Obama is hosting a dinner for the spouses of NATO dignitaries during this weekend's summit in Chicago Sunday, May 20, 2012. (AP Photo/Charles Rex Arbogast)

  • Protesters gather in the rain at the Art Institute where First Lady Michelle Obama is hosting a dinner for the spouses of NATO dignitaries during this weekend's summit in Chicago Sunday, May 20, 2012. (AP Photo/Charles Rex Arbogast)

  • A protester gestures in the rain at the Art Institute where First Lady Michelle Obama is hosting a dinner for the spouses of NATO dignitaries during this weekend's summit in Chicago Sunday, May 20, 2012. (AP Photo/Charles Rex Arbogast)

  • Police stand infront of the Chicago Art Museam during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (Cengiz Yar Jr./AFP/GettyImages)

  • A protester mimics police infront of the Chicago Art Museam during NATO Summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (Cengiz Yar Jr./AFP/GettyImages)

  • A protester is helped after sustaining an injury at a protest march and rally during this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Charles Rex Arbogast)

  • A protester is detained by police at a march and rally during this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Paul Beaty)

  • Protesters stand off with police during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (Cengiz Yar Jr./AFP/GettyImages)

  • A Chicago Police officer confronts a protester during a march and rally at this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Charles Rex Arbogast)

  • Protesters stand off with police during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (Cengiz Yar Jr./AFP/GettyImages)

  • Police move in during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (TASOS KATOPODIS/AFP/GettyImages)

  • Protesters stand off with police during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (Cengiz Yar Jr./AFP/GettyImages)

  • Protesters clash with police during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (TASOS KATOPODIS/AFP/GettyImages)

  • A protester is carry away during protests against the NATO summit in Chicago on May 20, 2012. Scuffles broke out at a Chicago protest which turned ugly when a few hundred anti-NATO demonstrators demanding an end to destructive wars refused police calls to clear the streets. An AFP correspondent saw about a dozen protestors roughly hauled away as they tried to muscle through a police cordon around a convention center where NATO leaders have gathered for a two-day summit. (TASOS KATOPODIS/AFP/GettyImages)

  • Protester bloodied in clashes with police

    <a href="http://www.huffingtonpost.com/social/linesarefuzzy"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/linesarefuzzy">linesarefuzzy</a>:<br />Protester bloodied in clashes with police during NATO protest in Chicago, May 20, 2012

  • A couple of war veterans greet before throwing their medals towards McCormick Place, site of this weekend's NATO summit, during a rally in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Charles Rex Arbogast)

  • Chicago police scuffle with demonstrators during a protest march and rally at this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Paul Beaty)

  • A protester is detained at a march and rally during this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Seth Perlman)

  • A demonstrator and police face off during protest march at this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Charles Rex Arbogast)

  • Protesters march down Michigan Ave. in Chicago during this weekend's NATO summit Sunday, May 20, 2012 in Chicago.(AP Photo/Charles Rex Arbogast)

  • NATO leaders including President Barack Obama, pose for a photo at Soldier Field during NATO Summit in Chicago, Sunday, May 20, 2012. (AP Photo/Christophe Ena)