Nato Chicago protests target Boeing and Obama HQ
Protesters have demonstrated outside the Chicago offices of defence giant Boeing, a day after violent clashes by the venue of a Nato summit in the city.
Some demonstrators laid down near the building in a mock "die-in", although barricades blocked off the building and police officers stood nearby.
Activists also protested in front of President Barack Obama's re-election headquarters.
Dozens of activists were arrested during disorder on Sunday.
In that protest, several thousand protesters marched from Grant Park through the centre of Chicago to the site of the summit at McCormick Place. It was one of Chicago's biggest demonstrations in years.
The activists demanded an immediate end to US military involvement in Afghanistan, as well as action on climate change and economic inequality.
On Monday, about 200 to 300 people marched towards Boeing's offices to protest. Some chanted "we're gonna beat back the Boeing attack", the Chicago Tribune reported.
Boeing, a major US defence contractor, was among many downtown Chicago business that were nearly empty on Monday after the company allowed employees to work remotely.
Protesters seized on that as a victory: "Our call to action shut down the Boeing war machine," they said in a statement.
A Boeing spokesman told the Tribune the company "obviously" had a "difference of opinion" but the company had no problem with their protest "as long as they remain peaceful and respectful of our property".
Activists from the Chicago branch of the Occupy movement argue that tax breaks deprive the state of Illinois of millions of dollars in revenue from Boeing.
Occupy Chicago also objects to Boeing's role in producing fighter jets, bombs and missiles for the US and its Nato partners.
Protesters also marched to the building that hosts President Barack Obama's re-election headquarters.
Some at the site made speeches saying they were upset with Mr Obama over the ongoing conflict. But the protest, which finished as Mr Obama made a speech to the summit, was peaceful.
Veterans toss medals
Among the demonstrators on Sunday were 50 military veterans who threw service medals into the street near the summit site.
Clashes broke out as a small group of demonstrators tried to reach the convention centre where President Barack Obama is hosting the gathering of more than 50 world leaders in his home town.
The stand-off lasted for about two hours, with projectiles being hurled at a line of police, who replied by using batons.
More than 60 people were arrested, Sarah Gelsomino of the National Lawyers Guild, which represented protesters, told Reuters news agency.
One of those arrested was a freelance photographer who was covering the demonstration for Getty Images.
There was also a heavy police presence when hundreds of protesters gathered on Sunday night near the Art Institute of Chicago, where First Lady Michelle Obama was hosting a dinner for spouses of Nato leaders.