From pro-independence yellow crosses vying with Spanish flags on beaches to party offices vandalised,
"There is latent violence, violence that can be felt in the air but doesn't usually materialise into physical violence, and it's on the rise," warns Sonia Andolz, a political expert in conflict analysis at the University of Barcelona.
"There is a rise in tone, confrontation between people who push or insult each other. Hate speech against others is becoming normal."
Over the past weeks, this region of northeastern Spain with 7.5 million people has been the scene of a war of symbols.
Independence supporters have filled streets, buildings or beaches with yellow crosses or ribbons, the colour used to protest against the jailing of separatist leaders after a failed independence bid last October.
Those who want to remain in Spain then promptly remove these symbols.
Early this month, police had to intervene to prevent two groups from clashing in Barcelona.
Last week in Canet de Mar, some 40 kilometres (25 miles) north of the Catalan capital, three independence supporters were injured when a group of hooded people destroyed a "cemetery" of yellow crosses installed on the beach.
On Sunday, anti-independence protesters in Barcelona tried to force a police officer to remove a yellow ribbon hanging on the city hall, and then filled a beach with Spanish flags.
The conflict even reached the regional parliament where a session was interrupted on Friday because Carlos Carrizosa, a lawmaker for the main anti-independence party Ciudadanos, removed a yellow ribbon from a seat.
The political situation in Catalonia remains blocked as Madrid refuses to restore direct rule in the region because its new president Quim Torra has named four jailed and exiled separatist leaders as part of his regional government.
Attacks on party HQs
While the independence movement is far from new in Catalonia, tensions erupted in earnest after a banned independence referendum on October 1 which was marred by police violence.
The jailing of separatist leaders and a failed declaration of independence on October 27 -- rejected by around half of the population in Catalonia -- also provoked tensions.
Protests on both sides of the divide then increased.
While not a major force in Spain, far-right groups waded in, leaving a trail of assaults against independence supporters.
Meanwhile separatist protests that had always been peaceful started getting disruptive with demonstrators clashing with police in March.
Political parties have not been spared either.
They have denounced acts of vandalism against their offices, from graffiti to broken windows.
The office of Ciudadanos in L'Hospitalet de Llobregat, Catalonia's second biggest city, has been vandalised 13 times since 2015, says its manager Miguel Garcia.
Some of these acts involved filling the entrance with animal faeces.
"It's just another sign of the tension that Catalonia is going through, there are people who don't tolerate our ideas," says Garcia.
Ciudadanos has counted around 30 acts of vandalism in the northeastern region over the past year, a similar figure to that tallied by the Catalan branch of Spain's Socialist party, also against independence.
Pro-independence parties have also suffered but according to the ERC separatist party, they don't count them so as not to convert "one-off events into a category."
"Some want people to think that Catalan society is becoming radical and uses violence, but that's not true," says David Bonvehi from the PDeCAT, the party of deposed Catalan president Carles Puigdemont.
The PDeCAT saw one of its office in Barcelona covered in faeces on Monday.
In an article in Catalonia's La Vanguardia daily, writer Antoni Puigverd compared the situation in the region to the boiling frog syndrome.
That says if a frog is plunged into boiling water, it will jump out, but if it is put into tepid water which is then brought to a boil slowly, it will be cooked to death.
"This very low intensity violence, this vandalism, these ritual clashes... are the warm water in which the Catalan frog is bathing as it tries to ignore that the fire is still on, and every day the temperature rises a little," he wrote.
Andolz, who has experience mediating conflicts in the Balkans and Middle East, doubts that physical violence will become widespread but warns the situation "is more dangerous than it seems."
"In conflicts, physical violence is the worst but the easiest to stop," she says.
"Cultural violence and hate remain and that should be of huge concern."