LA PAZ, Bolivia (AP) — Striking Bolivian miners kidnapped and beat to death the country’s deputy interior minister in a shocking spasm of violence following weeks of tension over dwindling paychecks in a region hit hard by falling metal prices. The miners were demanding they be allowed to work for private companies, who promise to put more cash in their pockets.

The issue has bedeviled President Evo Morales, who began as a champion of the working class and privatized the nation’s mining industry, only to see his support crater amid the downturn. Miners say Morales has become a shill of the rich, and done little to help them make ends meet as the economy slows.

Deputy Minister Rodolfo Illanes, whose formal title is vice minister of the interior regime, had traveled Thursday to the scene of the violent protests in an effort to negotiate with the strikers who armed themselves with dynamite and seized several highways.

Instead, Illanes was “savagely beaten” to death by miners, Defense Minister Reymi Ferreira told Red Uno television, his voice breaking.

An autopsy found Illanes died from trauma to the brain and thorax. Seven miners’ leaders were detained by police, and their offices raided.

“This is a political conspiracy, not a social demand,” Morales said at a news conference Friday, accusing his opponents of backing the miners’ demands. He called for three days of official mourning, criticized the “cowardly attitude” of the protesters and insisted that his government had “always been open” to negotiation.

Illanes “was kidnapped, tortured and murdered,” Morales said.

Businessman and opposition leader Samuel Doria Medina rejected Morales’ comments about the opposition and said the government should try to make peace.

“The prices of minerals have gone down and the costs of production have increased,” he said. “That is the cause of the protest.”

“Morales would do well to be critical of himself and set aside false conspiracy theories blaming the right wing and the media,” former President Jorge Quiroga said, “when the undercurrent of these protests is the crisis.”

The fatal beating came after the killings of two protesters in clashes with police Wednesday, deaths that likely fueled the tensions.

Illanes, who was also a lawyer and university professor, had gone to Panduro, 80 miles (130 kilometers) south of La Paz, to open a dialogue with the miners. They had blockaded the highway there since Monday, stranding thousands of vehicles and passengers.

Officials said he was taken hostage by the miners Thursday morning. At midday Illanes said on his Twitter account: “My health is fine, my family can be calm.” There were reports that he had heart problems.

Illanes’ body was later found abandoned on the side of the highway, his car burned. Illanes’ driver escaped.

Labor Minister Gonzalo Trigoso said the highway was clear Friday morning, as the miners returned to their camps.

Bolivia’s informal miners number about 100,000 and work in self-managed cooperatives that primarily produce zinc, tin, silver, gold and lead concentrates. They want to be able to associate with private companies, but are currently prohibited from doing so. The government argues that if they associate with multinational companies they will no longer be cooperatives.

The influential National Federation of Mining Cooperatives of Bolivia, a strong ally of Morales when metal prices were high, was organized in the 1980s amid growing unemployment in the sector that followed the closure of state mines.

Federation members went on an indefinite protest after negotiations over mining legislation failed. Strikers are also demanding access to new mineral deposits and subsidized electricity to help them handle the crisis in the mining sector.

Bolivia has seen increased social agitation as a financial slowdown hit an economy heavily dependent on natural gas and minerals, which account for over 70 percent of foreign export sales. Export earnings fell by about a third in the first half of the year. Though down from recent years, Bolivia is still expected to see GDP growth of about 3.9 percent in 2016, outperforming its South American neighbors.

Last month the country saw other protests following the closure of a state textile factory and elimination of more than 800 jobs. There has also been a long demonstration by disabled people who demanded a raise to their government subsidies.

Morales’ own political rise came through labor battles by coca leaf growers, who used road blockades as their main tactic.