More than 8,000 striking South African gold miners have been sacked after refusing to return to work, mine owners say.Gold Fields said workers at the KDC East mine had ignored a final deadline set for 16:00 (14:00 GMT).Last week, some 11,000 miners at Gold Fields' KDC West mine heeded a company ultimatum and returned to work.South Africa's mining sector has been hit by a wave of recent unrest which has left almost 50 people dead.Most strikes have been over pay, although the stoppage at KDC East - at Carletonville west of Johannesburg - relates to a local trade union dispute not wages."All 8,500 people who were on strike did not come back," spokesman Sven Lunsche told AFP news agency."They did not return to work, so we have issued dismissal letters to all of them."He said the miners had 24 hours to appeal against their dismissal."We have now reached a stage where we can't hold off any more. Our hands were forced and we have now done it," Mr Lunsche said."We are monitoring the situation very closely and have police on standby but it has been very quiet.Court rulingGold Fields had issued a final ultimatum to employees to present themselves for work starting with the night shift on Monday 22 October and the morning and afternoon shifts on Tuesday, or face immediate dismissal.It had secured a court order ruling the strike illegal.The unrest in South Africa's mining sector - one of the world's biggest - has badly hit the country's economy, with the rand losing value and its credit rating downgraded.President Jacob Zuma has urged workers to return to work and asked company executives to freeze their pay.Mr Zuma has also set up a judicial commission of inquiry into the killings of 44 people at the Marikana mine, 34 of whom were shot by police.The investigation will determine the roles played by the police, the management of the platinum mine, Lonmin, the unions and government.The shootings in August provoked widespread shock in South Africa and a wave of industrial unrest.