G-20 protesters clog Grant Street in Pittsburgh Friday in front of the Allegheny County Courthouse. The G-20 Summit finished up Friday evening.

PITTSBURGH — A vociferous but peaceful group of several thousand people marched for miles through the downtown area on Friday, united by opposition to the Group of 20 summit but expressing a diversity of mostly liberal causes as an army of stone-faced riot police watched their every move.

Dozens of black-clad anarchists were conspicuous among the demonstrators, but there was no sign of the disturbances that had resulted in arrests and property damage a day earlier.

Public safety officials said Friday night that 83 people were arrested at protests and other events and about $50,000 in property damage was done during the two-day summit, which ended Friday. They said a man who smashed store and business windows in the city's Oakland section on Thursday night was responsible for about $20,000 in damage. About 60 more people were arrested at an illegal gathering Friday night in the Oakland section of the city, near the University of Pittsburgh, police said early Saturday.

The main message of Friday's so-called Peoples' March to the G-20 was a demand for solutions to the planet's economic and environmental challenges different from those the world's richest countries are pursuing. But there also was a strong contingent of anti-war protesters and those interested in such diverse issues as African debt relief, rejection of corporate subsidies and more humane child-labor laws.

"We want money for jobs, not war, money to clean up the environment," said Pete Shell, a protest organizer.

President Barack Obama said the protests had been relatively peaceful, adding that previous world summits drew far more protesters than came to Pittsburgh. He described many as opposing capitalism and free markets in general, and said he supported their freedom to express their views but disagreed with them.

There also was a festive spirit in Friday's crowd — colorful flags, bicyclists, a group of hula hoopers, a large parade puppet in the shape of a dove, a small brass band and a correspondent from Comedy Central's "The Daily Show," who drew a mini-crowd of his own.