(Photo: CGTN)

Catalan independence activists obstructed major roads and a high-speed railway line in the east of Spain on Monday, one year after a controversial referendum that was opposed by the central government.

Hundreds of activists, many covering their faces with scarves, occupied the high-speed railway tracks at Girona station in the early morning, demanding that the regional government push ahead with independence.

Central streets in Barcelona and Lleida were blocked, as was the AP-7 motorway, south of Barcelona, and A2 linking Barcelona to Madrid, images on Catalan TV showed.

The high-speed rail service linking Figueres, Girona, and Barcelona "was interrupted" since the "tracks in Girona are occupied," Spanish state-owned rail operator Renfe said on Twitter.

Some three hours later, they left the tracks and the service was restored, it tweeted.

Tensions remain high after last year's referendum in Catalonia on seceding from Spain, which Madrid dismissed as illegal.

Six people were arrested in Barcelona on Saturday after clashes between protesters and riot police.