A PRO-union rally in Barcelona turned violent yesterday as demonstrators wrapped in Spanish flags gave Nazi salutes and clashed with police.

Videos emerged on social media showing a Sikh trying to defend himself after being attacked by a man draped in a Spanish flag, and a unionist protester launching an attack at a journalist.

Others showed pro-unionist protesters goading officers from the Mossos d’Esquadra, the Catalan Police, by covering their vehicle windscreens and windows with Spanish flags and jeering as they tried to make their way through the crowds.

Josep Lluis Trapero, the force chief who is regarded as a local hero because of his officers’ handling of the Barcelona terror attacks, quit his job over the weekend before he was sacked by Spain’s central government, which has dismissed the entire Catalan cabinet.

Some in the crowd shouted that Carles Puigdemont, the sacked Catalan leader, should be sent to prison after his declaration of independence on Friday. Gangs could also be heard shouting “Viva Franco” – Spain’s late dictator General Francisco Franco – in another video.

Barcelona has seen huge pro-independence marches in recent months, some numbering more than two million people, but this was the biggest to date by their opposition with police estimating the crowd at around 300,000 people.

The organiser of yesterday’s protest – Catalan Civil Society (CCS) – said its goal was to defend Spain’s unity.

Rival pro-union parties from Mariano Rajoy’s ruling conservatives, the liberals and socialists joined together under the slogan “We are all Catalonia”.

CCS president Alex Ramons said: “We have organised ourselves late, but we are here to show that there is a majority of Catalans that are no longer silent and that no longer want to be silenced.”

Members of Rajoy’s government, including health minister Dolors Montserrat and Enric Millo, Madrid’s representative in Catalonia, also attended the rally.

Catalonia’s President Carles Puigdemont, who was sacked on Saturday, has called for Catalans to engage in peaceful opposition to Spain’s crackdown.

Rajoy also called a new regional election for December 21, and top pro-union politicians wanted to use yesterday’s rally as a launchpad for the crucial poll.

Albert Rivera, leader of the centre-right Citizens Party, said: “It’s time to take over the streets and take over the ballot boxes.”

In an open letter in Catalan newspaper El Punt-Avui, Oriol Junqueras, the ousted vice president of Catalonia, said independentists should consider taking part in the elections.