Street parties in Barcelona celebrating the victory of the city's soccer team in the Champions League final turned violent and at least 11 people were hospitalised, according to local media reports.
Police said more than 80 people were arrested after revellers attacked officers with bottles, flares and other objects, and destroyed park benches and bus stops.
The scuffles broke out hours after Barcelona beat Manchester United 3-1 at Wembley.
About 50,000 people flooded the streets of Barcelona to celebrate.
A police officer was among those hospitalised. AP photographs show plain-clothes police officers, who were wearing Barcelona shirts to blend in with the crowds, making arrests.
More celebrations were expected when the team arrives in Barcelona to tour the city with the Champions League trophy. The festivities will culminate when fans receive their team at the 98,000-seat Camp Nou Stadium.