Barcelona (AFP) - Clashes erupted in Barcelona late Wednesday after thousands rallied for a huge protest in the city centre, as Spain’s Prime Minister Pedro Sanchez made a direct appeal to the Catalan president to condemn the violence.

For the third night running, protesters clashed violently with riot police in the Catalan capital as they expressed their fury over the sentencing of nine Catalan separatist leaders to heavy jail terms over their role in a failed independence bid.

As Spanish television broadcast dramatic footage of blazing barricades and protesters hurling projectiles at a heavy contingent of riot police, Sanchez made a televised appeal for calm, urging Catalan leader Quim Torra to “clearly denounce” the violence.

“I want to call on the Catalan president: both he and his ministers have a political and moral duty to condemn very clearly – without excuses and without playing it down – the use of violence in Catalonia,” he said.

So far, Madrid has shown little appetite for taking matters into its own hands, despite the ongoing protests in Barcelona and elsewhere that have hit screens round the world as Catalan separatists have made their anger known.

The latest crisis began just over two years ago when Catalonia’s separatist leaders held a banned referendum then issued a short-lived declaration of independence, prompting Madrid to sack its government and suspend the region’s autonomy.

It also put 12 of its leaders on trial, nine of whom were condemned for sedition on Monday, and handed prison terms of between nine and 13 years.

At Wednesday evening’s demonstration in Barcelona, which was called by the radical CDR and drew thousands of participants, many began hurling toilet rolls into the air in response to a slogan by the movement saying there was “a lot of shit to clean up”.

As tensions mounted, they began whistling at police and shouting: “The streets will always be ours”.

- Street rage -

Two days earlier, some 10,000 protesters swarmed Barcelona’s El Prat airport, cutting off transport links and forcing the cancellation of more than 100 flights.

Riot police charged at the demonstrators on several occasions, firing foam rounds into the crowds, with the emergency services saying 115 people were injured, including a protester who lost sight in one eye.

A day later, hundreds of protesters, many of them masked, fought running battles with hundreds of riot police, hurling projectiles and torching barricades, with 125 demonstrators and 72 police officers injured, officials said.

The protests continued Wednesday, with thousands of people joining five mass marches from towns throughout the region heading for Barcelona, with the aim of causing chaos on the roads in one of Spain’s most important economic regions, which is also a bottleneck for traffic with France and elsewhere in Europe.

The marchers plan to converge in Barcelona on Friday when unions have called a general strike in the region.

As the wave of protests continued, Spanish premier Sanchez held emergency talks with opposition leaders Wednesday over the unrest.

In recent weeks, Sanchez has made clear that his government will not tolerate any violence, warning he will not hesitate to renew a suspension of Catalan autonomy, with his office saying he “does not rule out any scenario”.

- Catalan president condemns.. verdict -

After the talks, Pablo Casado, who heads the main conservative opposition Popular Party, urged the government to take a harder line to stop the “inadmissible escalation of violence”, while Pablo Iglesias, who heads the radical leftwing Podemos called for measures to lower the tension.

The court ruling and sentences have thrust the Catalan dispute to the heart of the political debate ahead of Spain’s November 10 general election, its fourth in as many years.

The unrest prompted Spain’s football league to request on Wednesday that the clash between arch-rivals Barcelona and Real Madrid, which is due to take place on October 26, be moved from Barcelona to Madrid.

The violent protests marked a break with the mainly peaceful and festive pro-independence rallies which have been held in Catalonia since the separatist movement gained momentum nearly a decade ago.

While Catalan president Torra has sanctioned and even encouraged civil disobedience, his government is also responsible for the regional police who are charged with controlling demonstrations, putting him in an uncomfortable position.

When asked about the clashes as he took part in one for the mass protest marches that set out from Girona, he only had one condemnation to make: of the “sham verdicts” that followed the “sham trial” of the separatist leaders.