20 Minutes Online reports that the authorities were 'astonished' when protesters set off smoke bombs and flares outside the city prison.

The police claim this is why they then fired rubber bullets at the demonstrators who had gathered under the rallying call of 'Justice for All - Against Police Violence'.

Anti-police rioting erupted during the evening and more than 40 people were arrested.

Explaining the background to the protest, Swiss Indymedia says that on Sunday 18 April, an 18 year old called Sebastien from Vaulx-en-Velin was killed by Swiss police.

After the theft of three vehicles, police organised an ambush and shot him dead at a roadblock.

A leaflet against 'social pacification' was handed out by protesters on the day.