“All the indications are that our deputy minister Rodolfo Illanes has been brutally and cowardly assassinated,” Carlos Romero, the minister of government, said late on Thursday in comments quoted by the Reuters news agency.
He said that the 56-year-old had gone to talk to protesters earlier on Thursday in Panduro, around 160km from the capital, La Paz, but was intercepted and kidnapped by striking miners.
The government was trying to recover his body, Romero said.
Local media also reported Illanes’ death, citing a radio station director who claimed he saw his body.
Protesters have been demanding more mining concessions with less stringent environmental rules, the right to work for private companies, and greater union representation.
Protests turned violent this week after two workers were killed on Wednesday after shots were fired by police. The government said 17 police officers had been wounded.
The National Federation of Mining Cooperatives of Bolivia, once strong allies of leftist President Evo Morales, began what they said was an indefinite protest after negotiations over mining legislation failed.
Morales nationalised Bolivia’s resources sector after taking power in 2006, initially winning plaudits for ploughing the profits into welfare programmes and boosting development.
However, his government has been dogged by accusations of cronyism and authoritarianism in recent years, and even the unions who were once his core support have become disillusioned with him as falling prices have limited spending.