As the match at the Nou Camp approached the hour-mark, referee Alejandro Hernandez Hernandez was forced to stop play as fans pelted the pitch in what appeared to be a pre-planned protest.

Some of the balloons had written on them "Youngster, the republic needs you", while other bore the message "Sit and Talk".

The Liga fixture was being played on Wednesday night having already been postponed from its initial 26 October date to due to unrest in the Barcelona area, where protesters in favour of Catalan independence caused the match to be moved out of a fear for public safety.

The build-up to Wednesday night’s match passed largely without incident, with protesters outside the Nou Camp choosing to display flags and banners while marshalled by hundreds of police deployed by authorities to keep the peace.

A yellow balloon reading "Youngster, the republic needs you" thrown onto the Nou Camp pitch (Getty)

A steward helps to clear the pitch during a protest at El Clasico (Getty)