For years, Catalonia’s separatist movement painstakingly built an amiable image of its quest to secede from Spain:

Smiling parents and grandparents with children in tow marched under the Mediterranean sun, waving the flags of their cause and cheerily chanting “independence!”

But over the course of this week, that friendly face was replaced by the snarling visage of a furious young man hurling gasoline bombs and chunks of pavement at police struggling to contain riots that have turned downtown Barcelona and other towns in the wealthy northeastern region into no-go zones at night.

For four successive nights, protests have spiraled out of control come nightfall, with demonstrators burning cars and hundreds of trash cans, causing 1.1-million-euros-worth of damage ($1.2 million) and eventually clashing with police in Barcelona, a leading European tourist destination. Fires also raged in other towns across Catalonia, an industrial powerhouse region that is home to 7.5 million people and has its own language and cultural traditions.

Authorities said that nearly 100 people were injured, almost half of them police officers. A total of 97 protesters have been arrested since Monday, including four sent to jail while authorities investigate them for public disorder.

Police said the protesters hurled gasoline bombs, acid, stones, firecrackers, nails and bottles at them. Fireworks hit a police helicopter, although no major damage was caused. Outnumbered regional and national police responded with foam and rubber bullets, batons and shields. A 17-year-old boy was recovering from a head injury caused when a police van charged into a trash container he was hidden behind in the city of Tarragona. Another protester lost an eye earlier this week.

Images of a father holding his baby after they had to flee their apartment in downtown Barcelona for fear that the flames would reach their building have shaken the city.

Peaceful protests like those that long characterized the movement are continuing — including a student strike and marches that are set to converge on Barcelona on Friday. But they are being overshadowed by the chaos.

Text from the AP news story, Riots darken Catalan separatist dream of peaceful secession, by Joseph Wilson and Aritz Parra.