Around 600 union workers at Pan American Silver's San Vicente silver-zinc mine in the Potosí department of Bolivia have gone on strike, demanding changes in the senior management.
The workers are demanding the removal of general manager Eusterio Huerta León, reported Business News Americas citing union leader Hugo Arratia's update given to Página Siete newspaper.
Mining workers allege that Huerta León ordered increase of ore extraction by 50% to 1,200t a day and also banned the chewing of coca leaf at the mine.
The San Vicente mine is operated by Pan American's subsidiary Pan American Silver Bolivia in a joint venture with state-owned mining company Comibol.
Production activities ceased on 7 July. Only those personnel required for maintenance of key systems to allow smooth restart are being permitted inside the mine, the company said.
Pan American Silver said: "The company is continuing efforts to communicate with the union representatives and all interested parties in order to reach an amicable solution.
"At this time the strike has had no material impact on Pan American, however depending on the duration, the work stoppage could negatively impact the annual production forecast for the San Vicente mine and ultimately Pan American."
The company aims to produce 25.75 million ounces to 26.75 million oz silver and 155,000oz to 165,000oz gold this year.
Pan American has seven mines in Mexico, Peru, Argentina and Bolivia and several development projects in the US, Mexico, Peru and Argentina.