Police in Madrid made several arrests late Sunday night after a peaceful protest against government austerity measures ended in violent clashes.
Although rallies were held in 50 cities across the country, most of the confrontations were centred in the capital.
Many of the protesters were students complaining of not being paid enough or not being able to find jobs despite being highly educated.
Spain has one of the Eurozone’s highest jobless rates of 21.3 per cent with a record 4 .9 million unemployed.
Earlier in the day tens of thousands of students, social groups and some unemployed had marched under the banner of “ we aren’t merchandise in the hands of politicians and bankers.”