Spanish police have fired rubber bullets and smoke grenades at protesters as mass demonstrations continued in Catalonia last night.

Half-a-million people joined protests against the jailing of nine leaders of Catalonia's separatist movement over their roles in the push for independence in 2017.

The Spanish Supreme Court handed the leaders sentences of between nine and 13 years in prison for the charge of sedition.

The protests were largely peaceful; however police have clashed with masked demonstrators who threw rocks, bottles, eggs and paint at them.

Protestors wave Estelada pro-independence flags during a demonstration in Barcelona, 18-10-2019. Image: AP Photo/Emilio Morenatti

More than 200 people have been injured and nearly 100 arrested since the protests began on Monday, officials said.

Meanwhile, the Spanish Government has announced that the country’s national guard will be deployed in Barcelona.

The interior ministry said they would be deployed to the outskirts of the city.

Acting interior minister Fernando Grande-Marlaska also threatened protesters with potential jail sentences of up to six years.

Catalonia independence demonstrators in Barcelona, 10-18-2019. Image: Francisco José Pelay/Pacific Press/Sipa USA

Officers in riot gear responded by firing rubber bullets and smoke grenades and using batons and police vans to disperse a few hundred young protesters who surrounded the National Police headquarters.

Earlier on Friday, fugitive ex-Catalan leader Carles Puigdemont handed himself in to Belgian authorities after Spain issued a new warrant for his arrest.

His office said he had "voluntarily appeared before Belgian officials" while rejecting the warrant and opposing any attempt to send him back to Spain.

Unions from across Spain's northeastern region of Catalonia called for a general strike after Monday's Supreme Court ruling that saw nine politicians and activists jailed for up to 13 years over their role in a failed 2017 independence bid.

Catalan pro-independence demonstrators clash with police in Barcelona, Spain, 18-10-2019. Image: AP Photo/Bernat Armangue

Around 46 flights into and out of the region have been cancelled due to the latest industrial action.

Spain's biggest domestic football match, El Clasico, between Barcelona and Real Madrid, scheduled for 26 October, has been postponed to avoid coinciding with a large rally planned for that day.

Additional reporting from IRN