LA JONQUERA, Spain — Hundreds of Catalan pro-independence protesters blocked a border point on a highway that connects Catalonia with France on Monday, stopping traffic in both directions the day after a parliamentary election in Spain.

Since around 0800 GMT, the highway — an important truck route from France to southern Spain — has been cut at the border point of La Jonquera, with protesters on the French and Spanish side.

Traffic was diverted to another smaller road as protesters installed concrete barriers on the highway and set up a stage to hold concerts.

Catalonia has been rocked by mass protests since long prison sentences were handed down in mid-October to nine separatist leaders who spearheaded a failed independence bid in 2017.

The campaign for Catalan independence has been mostly peaceful for years, but some protests turned violent last month, with a minority of mostly young demonstrators torching cars and bin containers and launching petrol bombs at police.

Separatist Catalonian protesters block the border between France and Spain on Nov. 11, 2019 in La Jonqueera, Spain. David Ramos / Getty Images

Secretive campaign group Democratic Tsunami, which has organized mass protests including at Barcelona airport last month, claimed responsibility for Monday's disruption.

The group, which says it favors peaceful civil disobedience, said on Twitter its goal was to call upon the international community "to make the Spanish state understand that the only way is to sit down to talk".

Santiago Abascal, the leader of the far-right party Vox, which after Sunday's election became the third-largest party in parliament, said the road blockage was "unacceptable".

There was a "wide deployment" of Catalan regional police including anti-riot officers on the Spanish side of the border, a police spokeswoman said.

On the French side, local police were also present. There were some moments of tension with protesters, including when police told them to let some trucks to turn around but the protesters declined to do so.

The Spanish Confederation of Goods Transport said the highway blockage could have a daily economic impact of 15 million euros ($16.5 million).

Dulse Diaz, the confederation's spokesperson, said 20,000 trucks cross the border at La Jonquera every day in both directions.

Democratic Tsunami had said last week that it would organize a three-day protest from Monday that would be its "most ambitious" action.