SAO PAULO - Independent truckers in Brazil started an indefinite strike on Monday, blocking traffic in a few states in the agricultural powerhouse as they asked for President Dilma Rousseff’s impeachment, according to federal highway police. Roads were blocked in a handful of places in coffee-growing Minas Gerais and No. 2 soy state Parana, as well as in Santa Catarina. There were protests in the southern state of Rio Grande do Sul, but traffic was not blocked, police said. Local media said the strike had also reached the states of Espirito Santo, Rio Grande do Norte, Sao Paulo and Tocantins. A two-week truck strike in late February blocked roads at more than 100 sites in six states. The federal government is negotiating with independent truckers to try to prevent a prolonged strike and supply shortages. Brazil’s animal protein association warned that pork and poultry shipments could be disrupted in a crucial month for the sector, with demand from key buyers in the Northern Hemisphere increasing ahead of their winter. The sector lost some 700 million reais ($184 million) due to the roadblocks in February. Brazil is the world’s top exporter of soybeans, coffee, sugar and beef. The February strike included specific demands such as controlling rising diesel costs and implementing minimum freight rates, concerns organizers still do not believe have been met. But this protest is more political in nature and includes calls for Rousseff’s impeachment. The truckers’ protest comes at a time of deepening discontent in Latin America’s largest economy, complicating negotiations. “If we had a list of demands, the government is always open to dialogue, but this is a strike with a sole purpose of wearing down the government,” Rousseff’s spokesman, Edinho Silva, said. The country’s main trucking unions are not participating in the strike. An informal group called the National Transport Command, which has been organizing the demonstrations online, has more than 39,000 Facebook followers. A video posted by the Command late on Sunday said they were fighting to end corruption and for more opportunities for all Brazilians. ($1 = 3.8 reais)