Strikers shut world's top silver pit for 3rd day

MONTERREY, Mexico Dec 6 (Reuters) - Mexican miners at the world's top silver mine took their strike to protest the arrest of union officials into a third day on Saturday.

Workers laid down tools at the huge Fresnillo silver deposit in the central state of Zacatecas on Thursday. The union and mine owner Penoles (PENOLES.MX) said on Saturday the walkout was ongoing.

"All the workers remain on strike," a source at the union said. A Penoles spokesman said the large Madero and Sabinas zinc mines in Zacatecas also remained closed.

The Fresnillo mine produced some 33 million ounces of silver and close to 26,000 ounces of gold in 2007.

The strikes began after the Mexican government detained senior mining union members on fraud charges.

The union claims it is being unfairly targeted for its independence and for dragging out a 16-month strike at the giant Cananea copper mine owned by Grupo Mexico (GMEXICOB.MX).

Mexico arrested union officials Carlos Pavon and Juan Linares on Thursday. The leaders are accused of stealing funds given to the union after the privatization of Cananea, the country's top prosecutor said.

The head of the union, Napoleon Gomez, is living in Canada to avoid arrest on these same charges, which he denies.

In Gomez's absence, Pavon is the union's main spokesman and at the forefront of the strike at Cananea and two other mines belonging to Grupo Mexico.

The long-running strikes began last year over complaints about health and safety conditions but have been complicated by bad blood between union leaders and the company. (Reporting by Robin Emmott; Editing by Eric Beech)