Johannesburg - About 9 000 workers at Lonmin [JSE:LON] Marikana operations in Rustenburg are to be served letters of dismissal, the National Union of Mineworkers (Num) said on Tuesday."Last night, Lonmin said they will dismiss all 9 000 workers on the basis that they had disrupted operations since last week," said Num spokesperson Lesiba Seshoka.This followed disruptions at the platinum mine during last week's elections over an issue which, said Seshoka, had nothing to do with the employer."We sent a team to talk to them to defuse the situation. They continued even though we spoke to them."He said workers were caught up in a union branch leadership dispute which had nothing to do with the employer."Unfortunately, the company cannot have such people and has to let them go."The union would make interventions to help people reapply for their jobs where required, but would not support those who "are on the wrong side of the law".It had a similar situation at engineering and construction company Murray & Roberts about two years ago when about 2 000 people were fired."When I spoke to Lonmin last night, they said around 9000 people (are affected)," said Seshoka.Comment was not immediately available from a Lonmin spokesperson.