A Chinese mining group has denied violating human rights at Zimbabwe's Marange diamond fields where unlicensed small-scale miners have clashed with security forces in the past...Human Rights Watch (HRW) said...that police and private security employed by some mine owners were shooting, beating and using attack dogs against unlicensed miners. "There are no human rights issues here at Anjin," Munyaradzi Machacha, a director at Anjin [joint venture Zimbabwe Mining Development Corporation & Anhui Foreign and Economic Construction Company], told journalists...Four companies operate the mines. Two of them had already said reports of abuses were false: Diamond Mining Company of Zimbabwe -- a new joint venture between the government and Pure Diamond of Dubai -- and Mbada Diamonds...Three of the mining firms have been certified to export rough diamonds by global regulator Kimberley Process, a scheme that imposes requirements on member states to ensure gems were not obtained as spoils of conflict.