South Africa's largest union threatened on Friday to bring gold and platinum mining and other industries to a halt next week in a strike to support a stoppage by 1.3 million state workers. The strike by state workers seeking pay raises more than double the inflation rate started last week and has led to school closures, prevented medical treatment and caused bodies to pile up at state-run morgues. The National Union of Mineworkers said its members would launch the solidarity strike next Thursday, limited to one day for now but it could be prolonged which would deal a blow to the country's mining sector - responsible for 5 to 6 percent of South Africa's gross domestic product. NUM is the biggest union in the country's largest labor federation Cosatu, which says it has 2 million members and on Thursday filed seven-day strike notices that would allow members in affiliated unions to strike.. “The NUM fully supports the public sector strike and would next week Thursday ensure that every mining operation, every construction site and every energy worker joins the public sector strike in different forms,” it said in a statement. South Africa is the world's fourth largest gold producer and largest platinum producer, with mines turning out about 488 kg (1,076 lb) of gold and 385 kg of platinum a day. The country's biggest firms, such as Anglo Platinum, Impala Platinum and Harmony Gold Mining, have stockpiles of the precious metal and would not be hard-hit if it was a one-day work stoppage. Thousands of municipal workers defied a court order and staged a one-day sympathy strike on Friday that slowed garbage collection in major cities.