Spanish police in anti-riot gear fired rubber bullets and swung truncheons to disperse peaceful protesters in the Plaza de Cataluna square in Barcelona.
They were called in when about 50 people sat down on the streets to block a convoy of cleaning trucks who wanted to dismantle tents erected by protesters in the square.
It’s reported that about ten people were taken to hospital mostly for multiple bruising and psychological shock after the clashes.
It was the first attempt by police to remove demonstrators from the area.
Police said it needed to be clear in case Barcelona beat Manchester United in the Champions League football finals at Wembley.
Protesters started a nationwide campaign over soaring unemployment, corruption and welfare cuts.
Activists have vowed to return.
Meanwhile in Madrid’s Puerta del Sol square hundreds of demonstrators showed their solidarity by carrying flowers.