The riots in France – triggered by the police shooting of a 17-year-old in Paris – spread to Switzerland on Saturday evening.
Vaud police say violence broke out in the Flon district of Lausanne. Around 100 young people were involved as shop windows were smashed.
The rioters threw cobble stones at the police – and at least one petrol bomb was thrown.
Seven people were arrested. Six were under the age of 18 and a 24-year-old man.
Police say it seems the riot was organised on social media channels.