Violence erupted in South Sudan when President Salva Kiir, a member of the Dinka ethnic community, accused former Vice President Riek Machar, a member of the Nuer community, of waging a coup. Machar was sidelined in July when Kiir reshuffled his Cabinet and denies the allegations.
Daniel Bekele, director of African programs at Human Rights Watch, said both parties to the violence were targeting civilians along ethnic lines.
"Both sides need to leave civilians out of their conflict, let aid groups reach people who need help and accept a credible, independent investigation into these crimes," he said in a statement Thursday from Nairobi.
Representatives from both sides are trying to find a non-violent solution to the conflict at the negotiating table in neighboring Ethiopia.
The United Nations last month agreed to increase the troop strength for its peacekeeping in South Sudan, which estimates at least 10,000 people may have died since conflict began Dec. 15.