PITTSBURGH  Several thousand demonstrators espousing and denouncing a host of causes converged on downtown Pittsburgh on Friday, chanting, pumping up signs and playing instruments in a peaceful and permitted march calling for solutions to a range of problems that they attributed to the economic policies of the world leaders at the Group of 20 meeting.

Protesters with Iraq Veterans Against the War, wearing fatigues, marched alongside Tibetans chiming cymbals, chanting denunciations of China and waving signs, like one that read “G20 Let’s Talk Tibet.” Students for Justice in Palestine assembled on Forbes Avenue and called for an end to “the Israeli occupation.” Others held up signs like “We Say No To Corporate Greed,” and “We say yes to human needs.”

One group held aloft with bamboo poles a giant fabric replica of a dove. A marching band with a French horn, several snare drums and a trombone played amid a sea of black, American and Palestinian flags.

Image There was a heavy police presence downtown as the march wound through the planned route. Credit... Damon Winter/The New York Times

The People’s March, as it was called, was sponsored by the Thomas Merton Center, a Pittsburgh peace organization. It came a day after raucous confrontations between the police and protesters resulted in 66 arrests. At least five people needed medical attention, and about 19 businesses sustained damage.