Catalans are taking part in a general strike called after a police crackdown during Sunday’s controversial independence referendum.
In Barcelona, metro stations were closed, main roads were blocked by pickets and civil servants walked out.
Tens of thousands took to the streets in protest to Spain’s response to the vote, which was deemed illegal by Madrid.
Almost 900 people were injured during clashes at the weekend when riot police tried to stop people voting at polling stations.
Images of armed officers using batons and rubber bullets on peaceful voters were widely condemned.
The industrial action, affecting many services under the control of the Catalan government, was originally billed as a region-wide general strike.
But the country’s largest unions did not take part and the response to the strike call was patchy outside of Barcelona. Some shops, supermarkets and cafes stayed open.
Unions have called for dialogue between the two governments, criticising both the call for independence and the heavy-handed police tactics.
The referendum went ahead despite being banned by a Spanish constitutional court, with 90% of those who took part backing a split from Spain.
However, only around four in 10 of the region’s population voted, with many anti-separatists apparently choosing to stay at home.
Catalan leaders are mulling a possible declaration of independence this week following the poll.
The EU Commission, which also said the referendum was not legal under the country’s constitution, has called for talks to break the stalemate between the Madrid and Catalan governments.
Meanwhile, Barcelona player Gerard Pique, who supported the independence vote, has said he could quit the national team if insults by Spain fans continue.
The side is preparing for two World Cup qualifiers against Albania and Israel.
The Catalan defender has already announced he will retire from international duty after the 2018 World Cup in Russia, having grown tired of being criticised.