The protests come after 12 Catalan separatist leaders were sentenced to long prison terms. Many in Catalonia have long struggled for the region to gain an increased autonomy from Spain.
During the afternoon and evening, protesters and police have come together. Demonstrators must have thrown stones at riot police and set fire to garbage containers.
The news agency AP writes that the Spanish interior minister says that 128 people have been arrested. The police use rubber bullets and tear gas against the protesters.
The demonstration has announced a general strike and five different protest trains have marched and then met in the city center.
Protesters have during the day blocked the highway that runs between France and Spain. They have mistakenly blocked 20 major roads in the region. The BBC reports. The city's perhaps best known and well-visited tourist destination, the church of Sagrada Familia, has also been closed.
According to British the Express, 57 flights were canceled due to the protests.