Around 500 people participated in the demonstration on Saturday night but a smaller group of around 50 masked individuals was held responsible for the damage estimated in the tens of thousands of francs, according to the latest estimates.
The Tribune de Genève newspaper described the troublemakers as an “extremist fringe of Swiss anarchists and anti-capitalists animated by a desire to defy the state”.
The offices of banks were targeted along with the Grand Théàtre, Geneva’s opera house, and other businesses, including one run by a prominent right-wing MP, Eric Stauffer of the Geneva Citizens’ Movement (MCG), the newspaper said.
The windows of at least 20 businesses were smashed, while graffiti was spray-painted on dozens of buildings, Geneva cantonal police said.
The demonstrators gathered initially at a park behind Geneva’s train station and walked through the city centre to the opera house, where the facade and statues were defaced with paint.
The incidents occurred while the canton of Geneva remained under a state of alert, initiated more than a week earlier, over a possible terrorist threat linked to jihadists.
Police chief Monica Bonfanti defended the response of the force to the demonstration.
Officers were aware that a rally was planned but they were not aware precisely what the intentions of the group were, Bonfanti told the Tribune.
“With this type of gathering, the goal of police initially involves observing the situation to know what to expect, then to prevent possible outbreaks by securing particularly sensitive places, such as the Rue-Basses (a major shopping precinct), official buildings, including police buildings.”
Bonfanti said the objective was to “manage” the demonstration and a confrontation with the group would have only accentuated the problem.
Police have made no arrests but are studying video surveillance footage to track down the culprits, she indicated.
The demonstration was initially called on social media to protest budget cuts for “alternative culture” sites while support for "bourgeois culture", such as the opera, was maintained.