Sudanese rights organizations say atrocities are being committed as part of the ongoing conflict in the country's western region of Darfur. In this exclusive report, CNN has uncovered evidence that Russian mercenary group Wagner is complicit by its continuing support of Sudan's Rapid Support Forces paramilitary. As part of this investigation, CNN verified and corroborated incidents of rape perpetrated by the RSF, including one captured on video. The RSF denies links to Wagner and any involvement in mass rape. CNN's Nima Elbagir reports.