MADRID â?? Taxi drivers across Spain set off fire*****ers and threw objects at police yesterday as they went on strike to protest the increase in cars run by private companies like Uber that offer cheaper, mobile ride-hailing services. Travelers arriving at Madrid's or Barcelona's airports and train stations found **ne of the usual lines of Taxis waiting to pick them up. The strike was directed against the San Francisco-headquartered Uber and Madrid-based Cabify services. Unions claim these companies flout a law that stipulates there should be one private company vehicle for every 30 Taxis and promote unfair competition. Thousands of taxi drivers staged a demonstration in central Madrid at **on, with some setting off fire*****ers and hurling plastic bottles of water and eggs at police cordoning off access to Parliament. Some brief scuffles with police also occurred but there were ** immediate reports of arrests or injuries. Eduardo Martin, president of Unauto VTC association representing both private companies, said there had been more than 30 acts of aggression against their cars and accused taxi drivers of acting with impunity. The strike was to last from 6 a.m. to 6 p.m. in Madrid while in Barcelona it was due to end at midnight.