...[Four] South African miner[s]...died...in violence at strike-hit platinum mines, police said...Lonmin hoped more miners would return to work this week after it made its wage offer directly to employees, sidestepping the majority Association of Mineworkers and Construction Union (AMCU) in a bid to end a four-month strike. But violence related to labour disputes...escalated...after the number of employees reporting for work started to increase...In a joint statement...Lonmin, Amplats and Impala reported at least 20 assaults...and several serious incidents of intimidation against employees...National Union of Mineworkers (NUM) and...Solidarity [U]nion...said their members returning to work were being intimidated. "If Lonmin wants our members to return to work they have to guarantee their safety," said NUM spokesman Livhuwani Mammburu...The strike highlights the discontent among black miners who feel they are still not reaping the benefits of the country's mineral wealth two decades after apartheid ended.