1 MIN. DE LECTURA
LIMA, May 18 (Reuters) - Unionized workers at mines in Peru started an indefinite strike on Monday in a bid to press the government to strengthen labor laws, the head of the national mine workers union said.
The work stoppages scheduled at several mines threaten to curb mineral production in Peru, the world's third-biggest copper, silver and tin producer and seventh-biggest gold producer.
Workers are demanding the government repeal a law passed last year that eases rules on firing workers, and want it to restrict the use of contract workers by mining companies, said Ricardo Juarez, the president of the national mining federation.
The strike also aims to halt legislation that mining unions say reduces benefits and workplace inspections.
Some 20,000 workers are part of the national mine workers union, Juarez said.
Reporting By Mitra Taj; Editing by Richard Pullin