Dutch farmers protested government plans to cut nitrogen emissions by dumping manure and garbage Wednesday on highways and setting fires next to roads — the latest actions in a summer of discontent. Police urged them to stop for safety reasons and are investigating who was responsible. Road traffic authorities said several roads in central and eastern Holland were completely or partially blocked by roadblocks in the early hours, and fire services rushed to clear the roads as traffic increased. Clean-up operations were expected to last hours on some roads. Dutch media reported that at one location, he left a sign that read: “Sorry for the inconvenience, Rutte IV is leading us to despair,” a reference to the government of Prime Minister Mark Rutte, the fourth coalition he has led. Police and security officials appealed to farmers to stop what they described as dangerous situations. “Protest is a fundamental right and as long as it remains within the bounds of the law, much is possible,” emergency services said in a joint statement. However, they said the latest actions “seriously compromise road safety and can lead to life-threatening situations for road users”. The latest protests came a day after a government-appointed mediator sent invitations to farmers’ organizations to discuss with the country’s ruling coalition ways to reduce nitrogen emissions. “I see the talks as a turning point: to break the deadlock together,” said mediator Johan Remkes. “The cabinet has assured me that there is scope and joint solutions are possible.” However, some farmers have rejected the appointment of Remkes as an independent ombudsman because he is a member of Prime Minister Mark Rutte’s centre-right political party and a former deputy prime minister. Farmers are angry at government targets to curb emissions of nitrogen oxide and ammonia which they say threatens to destroy their farming way of life and put them out of business. The government says emissions of nitrous oxide and ammonia, produced by livestock, must be drastically reduced near natural areas that are part of a network of protected habitats for endangered plants and wildlife that stretches across the 27-nation European Union . The ruling coalition wants to cut emissions by 50% nationally by 2030, calling the measure an “inevitable transition” to improve soil, air and water quality in an EU state known for intensive farming practices of. It called on provincial authorities to draw up plans to reduce emissions and set aside an additional 24.3 billion euros (US$24.6 billion) to finance the changes. Farmers argue they are being unfairly targeted, while other industries such as aviation, construction and transportation also contribute to emissions and face less extensive rules. They also say the government is not giving them a clear picture of their future amid the proposed reforms. Earlier this year, farmers blocked highways with tractors and blockaded supermarket distribution centers.