Chanting "Black lives matter", "No Justice, no peace", and "Say his name: George Floyd", the protesters, most clad entirely in black, snaked through the centre of Switzerland's financial hub, joined by thousands more in other Swiss cities.
Demonstrations have been held around the world against racism and police abuses since the death of African American George Floyd in Minneapolis last month.
Even though Swiss gatherings of more than 300 people are banned to help curb the spread of the new coronovirus, police said they would tolerate the unauthorised assembly as long as it remained peaceful.
As the main march was dispersing, authorities clashed with a separate group of around 300 leftist agitators gathered in a square in the city centre who were throwing stones and bottles, police said.
Police used pepper spray and detained several people. One policeman was hurt.
