Convoys of Spanish truckers and farmers launched protests to demand fuel tax cuts on Friday, joining a wave of demonstrations across Europe. Transport workers joined forces to slow traffic on the main road skirting Barcelona Spain's second-largest city - and farmers' groups began similar action in Merida in the heart of the southwestern Extremadura agricultural region. The regional government warned Barcelona residents to avoid driving during the morning rush hour, as convoys of trucks, buses, taxis and ambulances caused traffic snarls at major crossroads. They reported several tailbacks of more than 1 km (half a mile) long, but no major disruption was reported in the city centre, where thousands of children returned to school for the first day of term. “The protest is a success. There are approximately 200 trucks and taxis involved. We're now waiting to hear from our counterparts in Madrid to see what our next step will be,” said Pedro Alberola, spokesman at UPTC truckers' association. In Merida, more than 700 vehicles including a battery of tractors were concentrated around the main four entrances to the city centre, along with a rally in which around one thousand people took part. “Apparently, there are more participants than we were expecting,” Lorenzo Ramos, secretary of farmers' association UPA, told Reuters. The groups were protesting the government's refusal to reduce fuel taxes despite the rise in crude oil prices to the highest levels for nearly 10 years. But government spokesman Pio Cabaniallas warned that the protests were futile