Catalan pro-independence union CSC called the strike which was supported by civic groups Asamblea Nacional Catalana (ANC) and Omnium Cultural, whose leaders were imprisoned last month on sedition charges.
Scores of people stood across dozens of major highways in the region waving placards and chanting “freedom for political prisoners” while minor scuffles were reported on social media as police attempted to move protesters, TV and video images showed.
One crowd of activists also forced their way into the train station in the city of Girona and protested on the tracks, causing delays, images on social media showed.
However, despite transport delays, shops and businesses in the region largely appeared to be functioning as normal.