 Peru's miners want better pay and improved labour rights |
Trade union officials said 40,000 miners had joined the strike but the government said only a few thousand miners were participating.
Labour Minister Susana Pinilla said the strike would be declared illegal later this week, allowing companies to fire workers absent for three days in a row.
Peru's biggest gold and copper mines said work was continuing as usual.
Peru is the world's second-largest silver producer and third-largest producer of copper and zinc and the industry is crucial to Peru's economy.
The unions complain that higher world prices for minerals have not trickled down to provide better pay for miners.
They also want President Alan Garcia to fulfil an election promise to protect jobs.
The National Federation of Mining, Metallurgy and Steelworkers called for the walkout after four days of talks between unions and the government broke down.
The federation brings together 74 mining unions representing 22,000 workers out of Peru's estimated 110,000 miners.
Most of the country's mines are controlled by large multinational companies.
