Thousands of miners and metal workers in Mexico have begun lifting strikes after they walked off the job earlier this week to protest working conditions and to support their embattled union leader.

The workers went on strike after the Labor Ministry recognized leader Napoleon Gomez's opponent, Elias Morales, as head of the union.

The strikers, demanding better conditions, effectively shut down Cananea and La Caridad, Mexico's two largest copper mines, and Penoles, the world's biggest silver producer.

Both copper mines are owned by Grupo Mexico, which also owns the Pasta de Conchos mine, where 65 people died last month in an underground explosion. The cause of the blast is under investigation.

Some information for this report was provided by AP and Reuters.