Thursday night's Europa League tie between Athletic Club Bilbao and the Belgian side Anderlecht was marred by a series of crowd incidents both before and after the game.
Supporters of the Belgian team caused problems in the streets of Bilbao in the hours prior to the match, which ended in a 1-1 draw and three members of the police force suffered slight injuries.
The Belgian supporters lit flares during the match and following the final whistle, several hundred of them invaded the pitch, an action which some of the home fans responded to.
There were several minutes fighting until the police and security forces were able to restore order and surround the Anderlecht fans.
The visiting coach Ariel Jacobs described the scenes as the result of the 'euphoria' felt by his team' s fans, but Athletic Club President, Fernando Macua wa angry with the response of the security forces.
"We all came here to enjoy a game of football," he told Basque television station ETB.
"We do what the authorities tell us to do and if incidents like this happen, it is because they could have done more to stop it happening. The Anderlecht fans had been drinking abundant quantities of alcohol throughout the day," he highlighted.