Four police officers were injured and several dozen people were arrested in protests in which shop windows, including that of McDonald's on Wenceslas Square, were smashed.
The demonstrations, which also targeted a Kentucky Fried Chicken shop, were against the growing influence of multinational corporations and their effect on the environment. They began with an open air rock concert billed as the "Global Street Party '98", timed to coincide with the G8 summit in Birmingham, and ended with a punch-up in Wenceslas Square. This square was the cradle of the 1989 "velvet revolution" where a quarter of a million Czechs gathered and in the course of a week peacefully brought down their communist government.
In the years after 1989, Prague underwent a renaissance - politically, under its world-famous playwright president, Vaclav Havel, and economically. It became a magnet, too, for Western youth. What Paris had been to bohemian Americans in the 1930s, Prague became in the 1990s.
The once-quiet Charles Bridge, one of the city's most famous and elegant landmarks, became so crowded at all hours of the day with thousands of tourists and temporary residents, that it was scarcely possible to glimpse the bridge itself.
Czechs were not always enthusiastic about all the changes that were taking place. The tourism boom brought millions of pounds of much needed foreign currency, as Prague became a number-one destination in the holiday brochures. But Czechs themselves often felt left out of the loop. Radical economic change brought high unemployment and poverty. There was the constant tension, too, between the need to do everything possible to bring foreign money into the city and the need to preserve the distinctive character of Prague.
And while communist repression has gone, there have been big cuts in education and health spending, and there are homeless people on the streets.
The weekend violence came as several thousand people, protesting over these changes as much as alleged damage to the environment perpetrated by multinationals, left the concert and marched on the city centre. A small group hurled paving stones and broke the glass windows of McDonald's - the third such attack.
Mainstream environmental groups were quick to condemn the violence. Greenpeace regretted that the protest had been described as ecological, "because that damages the image of preserving nature and the environment". The chairman of the environmental pressure group Duha complained: "This is abusing the name of the environmental movement."
Martin Bursik, the Environment Minister, also drew a line between the demonstrations and other environmental groups. He invited Green organisations for a meeting yesterday, and argued: "Nobody can seriously think that the programme of the ecological movement equals looting and stealing salami."