The South African Commercial Catering and Allied Workers Union (Saccawu) on Friday began an indefinite strike at Walmart-owned Massmart, sparking concern this could spill over into the rest of the sector, which is already facing rising costs and a weak economy. 

Saccawu spokesperson Sithembele Tshwete said the union was “busy talking” to staff at other retailers who could inflict pressure on Massmart in the “form of a sympathy or secondary strike”, and the union would “announce this one soon”...