Protesters welcome G20 leaders in Pittsburgh

The skyline of downtown Pittsburgh, Pennsylvania, as the city prepares for the G20 summit of world economic leaders being held this week Photograph: Saul Loeb/AFP/Getty Images

Workers install sheets of plywood over windows on a building in advance of possible protests in downtown Pittsburgh Photograph: Paul J. Richards/AFP/Getty Images

Activists set up a tent city as a gathering point to demonstrate against the G20 meeting Photograph: Jim Young/Reuters

Daniel Giovannelli of Pittsburgh installs signs with the names of Darfur villages destroyed in Sudan since 2004. The signs were placed across the street from Phipps Conservatory & Botanical Gardens ahead of the summit Photograph: Carolyn Kaster/AP

A man walks past a protest banner displayed in downtown Pittsburgh Photograph: Chris Wattie/Reuters

US Customs and Border Protection agents tour downtown Pittsburgh during a security briefing Photograph: SAUL LOEB/AFP/Getty Images

Mary Adams and her daughter Sarah, 3, protest along with other Aids activists, demanding that the world's most powerful leaders help thousands who will die from the disease Photograph: Matt Rourke/AP

Activists carry mock coffins near the site of the summit as they protest against the policies of the world's wealthiest nations regarding Aids research and treatment funding Photograph: Eric Thayer/Reuters

A policeman looks through a pedestrian gap in a security fence near the Pittsburgh Convention Centre, the site of the G20 summit Photograph: John Moore/Getty Images

Demonstrators protest in front of a bank building, calling for a moratorium on foreclosures Photograph: Eric Thayer/Reuters

Demonstrators protest near the site of the summit Photograph: Eric Thayer/Reuters

Members of the Allegheny county police department patrol downtown Pittsburgh in advance of the summit Photograph: Win McNamee/Getty Images

Demonstrators in Pittsburgh call for free and fair education Photograph: ERIC THAYER/REUTERS

Protesters in Pittsburgh demand education equality Photograph: Eric Thayer/Reuters

A group of state troopers stand near a woman on a corner in downtown Pittsburgh Photograph: Chris Hondros/Getty Images

Tara Widner of Pittsburgh holds her sign in the rain in Mellon Square as she participates in a rally calling for healthcare reform Photograph: Carolyn Kaster/AP

Lisa Fithian, centre, joining the Three Rivers Climate Convergence, marches with other members of her group down the streets of downtown Pittsburgh. Two protest groups launched a lawsuit on Monday asking for a hearing into allegations of harassment by Pittsburgh police prior to the G20 summit Photograph: Carolyn Kaster/AP

A view of the Allegheny river where police prepare for the G20 summit Photograph: Jim Young/Reuters

A group of protesters rappel from the West End bridge over the Ohio river with a banner denouncing slow action on climate change near downtown Pittsburgh Photograph: Don Wright/AP

Members of the environmental group Greenpeace are arrested after they hung a banner from the side of the West End Bridge over the Ohio River. Pittsburgh Police said eight of the nine people were arrested and charged with various misdemeanours. A ninth person is being charged with conspiracy Photograph: Keith Srakocic/AP

A US military Humvee patrols the streets. Law enforcement officials vowed reportedly to scuttle plans by protesters to disrupt the G20 summit with an unprecedented show of force in the normally quiet western Pennsylvania riverfront city Photograph: Chris Hondros/Getty Images

A demonstrator kneels on a tapestry outside a rally Photograph: Eric Thayer/Reuters

AFL-CIO president Richard Trumka speaks at a rally Photograph: Eric Thayer/Reuters

Joan Jett and the Blackhearts perform at a rally Photograph: Eric Thayer/Reuters

Residents sit above Mount Washington at dusk on 23 September, overlooking downtown Pittsburgh, site of the G20 summit Photograph: John Moore/Getty Images