A general strike by 4 million Spanish workers — around one-fifth of the total workforce — against the country’s housing crisis was mostly peaceful on Wednesday, unions said, though by the evening clashes erupted in some areas of Barcelona and Madrid.

Workers endured stormy weather to set up picket lines, with large marches taking place in Madrid, Barcelona and cities across Spain less than three weeks before a snap general election.

In the evening, clashes between police and some protesters erupted in Barcelona. Footage captured by a reporter showed furniture on the street had been set on fire after the main march had ended.