Coal miners in Zambia are complaining about work conditions, contract breaches, and other problems at mines run by a "private" Chinese company.  See 
this New York Times article.  For more information about the incident where the Chinese managers shot four workers, see 
this article in allAfrica.com.  For a larger discussion of Afro-Chinese increasingly icy labour relations, 
see this article.  And for reporting on whether China is a blessing or curse for Africa, 
click here.