Barcelona fans after their Champions League victory over Manchester United
Violent clashes broke out around Barcelona's central square, after an estimated 50,000 fans celebrated the city's football team winning the Champions League trophy at London's Wembley stadium.
Hundreds of the club's fans threw bottles at police as celebrations drew to a close, reports ITN.
Riot police officers were seen in the streets and, according to local media reports, 50 fans were detained.
On Friday, the city centre had witnessed separate clashes involving hundreds of protesters angry about high unemployment and the government's anti-austerity measures.