Catalan separatists have blocked roads and clashed with police as Spanish ministers held a cabinet meeting in the regional capital Barcelona, and not in Madrid.
The decision to move the meeting failed to reduced tensions months after Catalan leaders were jailed for trying to break away from Spain.
Prime Minister Pedro Sánchez and Catalan leader Quim Torra had agreed on Thursday to an "effective dialogue" but there were violent scenes near the venue where the cabinet assembled.
Friday's meeting was convened exactly a year after the previous Spanish government held snap elections in Catalonia, a decision seen as provocative by pro-independence groups.
Earlier in the day, more than 20 roads across Catalonia, including the AP7 and A2 motorways, were blocked by protesters as police were deployed in large numbers.
On the AP7, which runs along the Mediterranean coast, protesters sat on the road with their hands in the air. Police dragged them from the carriageway.
The protests were co-ordinated by a radical group, the Committees for the Defence of the Republic.