Swiss police said on Friday that five of their officers were injured during clashes in Geneva in which police fired tear gas and water cannon at protesters marching in support of the Gaza flotilla intercepted by Israel.
The initially peaceful protest of about 3,000 people, which stopped traffic in the city center, degenerated late on Thursday as protesters approached a bridge.
Such confrontations are rare for Switzerland although pro-Gaza protests have been gathering momentum.
Israel's interception of the flotilla sparked protests in Geneva, Zurich and Bern, as well as in Italy and Colombia.
Footage shared with Reuters from Geneva showed water being sprayed on protesters, flares launched amidst the crowd, and riot police moving protesters away.
The police said in a statement on Friday that one person had been arrested and investigations were continuing after five of their officers were harmed.
A police spokesperson said on Thursday that tear gas and water cannon had been needed to control the demonstrations, and that protesters had been throwing objects and causing damage to property.
This week Israeli forces blocked about 40 boats in the latest flotilla trying to break through the blockade of Gaza and deliver aid to the Palestinian territory.
The boats were carrying more than 450 foreign activists including some Swiss nationals and Swedish campaigner Greta Thunberg.
