BARCELONA, Spain (AP) — Police in Barcelona have arrested seven people on suspicion of attacking cars that work with ride-hailing apps like Uber and Cabify as part of a protest by taxi drivers that turned violent on Friday. The attacks occurred after taxi drivers announced an indefinite strike protesting a regional government plan to regulate the ride-hailing services, which they argued was too lax.

Taxi drivers continued to block a major street in Barcelona on Saturday, and taxi drivers in Madrid are planning to go on strike starting Monday. Regional and municipal officials were reportedly meeting again later Saturday with representatives of the taxi drivers. Catalan public television showed images of protesters trashing cars allegedly used by the app-hailing services. One group smashed a car’s windows while the driver was still inside.