About 100,000 South African gold miners demanding higher wages stayed off work on Monday, bringing mines to a standstill in the top bullion producer's first industry-wide strike in 18 years. The action is the latest and biggest of a series of strikes in recent weeks in a country plagued by huge income gaps between the rich and mostly black poor, more than a decade after the end of white minority rule. "The strike is 100 percent countrywide, all our people, about 100,000 of them, are on strike," Gwede Mantashe, general secretary of the National Union of Mineworkers (NUM), told Reuters. The strike started on Sunday at 1600 GMT. "It seems all the gold mines have come to a standstill," Chamber of Mines head negotiator Frans Barker told Reuters. The strike had paralysed the South African mines of the world's No. 2 gold producer AngloGold Ashanti, fourth-ranked Gold Fields, sixth-placed Harmony Gold and South Deep, Barker said. He said the chamber, which negotiates wages on behalf of gold producers, estimated a daily loss of around 40,000 ounces of gold production and 130 million rand ($20.17 million) in combined lost revenue per day due to the strike. Two unions called the strike after rejecting the latest offer by the Chamber of Mines of a 4.5 to 5.0 percent wage rise plus bonus payments. Unions are demanding a rise of between 10 and 12 percent.