Separatists rallied in Barcelona on Monday, waving red and yellow striped flags and banging drums, in a show of support for independence after Madrid moved to block a referendum on the region’s split from Spain.
But protestors from left-wing groups including CUP and Arran sparked a counter-demonstration which saw hooded men burn the flags of Spain, France and the European Union.
Others burned a photograph of King Felipe of Spain.
Spanish news website ABC Espanol said around 4,000 radicals joined the protest, adding: “Radicals are always present. Yesterday they burned again the flags of Spain, France and the European Union.
“They also broke a photograph of King Felipe VI. And they chanted cheers in favour of ‘Terra Lliure’, the terrorist group dissolved in 1992.”
Away from the flames pro-independence supporters climbed on each others’ shoulders to form human towers, a Catalan tradition.
Others carried banners reading ‘We’re going to be a free country!’ and ‘Full of hope’ while wearing fluorescent yellow t-shirts with the word ‘yes’.
City police said on Twitter that around one million people took part, one of the highest turn-outs in recent years. Protesters said they hoped the vote would go ahead as planned on October 1.
The Constitutional Court last Thursday suspended the referendum after a legal challenge by Prime Minister Mariano Rajoy.
Police have since searched newspaper offices and printers for signs of any preparation for the referendum.
But the head of Catalonia’s regional government, Carles Puigdemont, told journalists on Monday: “It’s not an option that the referendum won’t go ahead.
“It’s 20 days away and we’ve already overcome many hurdles.”
Mr Puigdemont is facing criminal charges of misuse of public money, disobedience and abuse of office for organising the referendum.
Polls have shown support for independence has been waning in recent years with those wanting a separate state in a minority. However, a majority of Catalans want to vote on the issue.
(Additional reporting by Maria Ortega.)