Thousands of separatists clashed with police in central Barcelona Saturday just hours after some 350,000 demonstrators held a peaceful march in the latest mass protest over the jailing of nine separatist leaders.

There are fears Saturday's evening protest could turn violent
There are fears Saturday's evening protest could turn violent AFP / Josep LAGO

The day had started peacefully, with the city's streets turned into a sea of flags as a tide of humanity flowed down the wide avenue running from the waterfront to the city's towering Sagrada Familia basilica.

In Madrid, thousands joined a rally in support of Spain's territorial unity called by the far-right Vox party
In Madrid, thousands joined a rally in support of Spain's territorial unity called by the far-right Vox party AFP / OSCAR DEL POZO

On an unseasonably warm October afternoon, the masses waved flags, sang songs and chanted slogans, among them many youngsters, elderly people and families with children.

Police said some 350,000 people had turned out for the march which took place in the shadow of the Sagrada Familia basilica
Police said some 350,000 people had turned out for the march which took place in the shadow of the Sagrada Familia basilica AFP / LLUIS GENE

But as night fell, thousands joined a separate demonstration by the radical CDR, massing outside police headquarters on Via Laeitana shouting "Occupation forces, out!" and hurling coloured plastic balls and marbles at the riot police guarding the building.

Catalonia has been gripped by unrest since the controversial Supreme Court verdict on October 14 which unleashed a wave of huge demonstrations
Catalonia has been gripped by unrest since the controversial Supreme Court verdict on October 14 which unleashed a wave of huge demonstrations AFP / LLUIS GENE

Although police initially refused to engage, they eventually charged, using batons and foam rounds to try and break up the crowds who pelted them with bottles, rocks and fireworks, an AFP correspondent said.

AFPTV / Maud WATINE

Police said around 10,000 demonstrators had massed in the street, which was eventually cleared by about 11:00 pm.

As night fell, thousands gathered outside the police headquarters, prompting a tense standoff with police
As night fell, thousands gathered outside the police headquarters, prompting a tense standoff with police AFP / Josep LAGO

Catalonia has been gripped by unrest since the October 14 Supreme Court verdict which unleashed a wave of protest that quickly turned violent, with masked demonstrators clashing nightly with riot police.

Police said some 350,000 people had turned out for the march which took place in the shadow of the Sagrada Familia basilica
Police said some 350,000 people had turned out for the march which took place in the shadow of the Sagrada Familia basilica AFP / LLUIS GENE

More than 600 people have been injured in the protests, 367 of them civilians and 289 police, official figures show.

'We won't forgive October 1'

The crisis began two years ago when the region staged a banned referendum on October 1 that was marred by police violence, then issued a short-lived declaration of independence, trigging Spain's worst political crisis in decades.

Catalonia has been gripped by unrest since the controversial Supreme Court verdict on October 14 which unleashed a wave of huge demonstrations
Catalonia has been gripped by unrest since the controversial Supreme Court verdict on October 14 which unleashed a wave of huge demonstrations AFP / Josep LAGO

Saturday's main rally was called by the ANC and Omnium Cultural, the region's two biggest grassroots pro-independence groups that have organised the largest separatist protests in recent years.

Catalans remain sharply divided over the question of separating from Spain, with 44% in favour but 48.3% against, a recent poll showed
Catalans remain sharply divided over the question of separating from Spain, with 44% in favour but 48.3% against, a recent poll showed AFP / Josep LAGO

Marching down the spacious boulevard, demonstrators chanted "October 1, we won't forgive, we won't forget", breaking into loud boos and whistling as a police helicopter flew overhead.

As night fell, thousands gathered outside the police headquarters, prompting a tense standoff with police
As night fell, thousands gathered outside the police headquarters, prompting a tense standoff with police AFP / LLUIS GENE

"I feel really angry," said computer technician Marc, 26, who did not give his surname.

Demonstrators pelted police coloured plastic balls but later started throwing bottles and rocks
Demonstrators pelted police coloured plastic balls but later started throwing bottles and rocks AFP / LLUIS GENE

"The violence doesn't sit well with me but it's normal to have a bit of upheaval like we've seen in Chile and Ecuador," he said of a wave of mass protests in Latin America.

A protester bleeds after being hit by police during a demonstration outside the police headquarters
A protester bleeds after being hit by police during a demonstration outside the police headquarters AFP / LLUIS GENE

"There are different ways of protesting but we have one objective: independence."

'Not an option'

Catalans remain sharply divided over the question of separating from Spain, with polls showing 44 percent in favour and 48.3 percent against.

Speaking to reporters at the rally, Catalonia's separatist president Quim Torra said his government was with the people "because it is what they want.

"We will go as far as they want".

He had earlier pledged to push ahead with the controversial independence drive after meeting 800 local mayors who expressed support for secession.

"The show of unity we've seen this week shows the next step that we all must follow... We must all push ahead and exercise the right to self-determination."

Torra has made repeated appeals for dialogue with the Socialist government of Pedro Sanchez with the aim of securing Madrid's agreement for a referendum on independence, but they have fallen on deaf ears.

"What we will not talk about is the right to self-determination," Carmen Calvo, Sanchez's deputy, told journalists on Saturday.

"If.. the aim is to break up Spain's territorial unity and separate Catalonia from Spain, we simply cannot talk," she said.

"Unilaterally breaking the rules of the game is not an option."

Counter rally on Sunday

On Sunday, Catalans who want to remain part of Spain are planning a massive counter-demonstration to raise the voice of the region's so-called "silent majority".

Earlier, some 20,000 people gathered in Madrid in defence of Spain's unity, national police said, for a rally organised by the far-right Vox party, which has taken a very tough line on Catalan separatism and wants all regional pro-independence parties banned.

Although the faction only entered parliament in April, polls indicate it might become the third-largest party following the November 10 election.