Officials in South Sudan have accused anti-government forces of killing 127 hospital patients in Bor, a strategic town that has changed hands several times since fighting erupted in mid-December.
The government on Wednesday said the patients were killed during a December attack by forces loyal to former vice president Riek Machar.
Opposition representative Hussein Mar Nyot denied the accusations. In a VOA interview, he said the government has been issuing "propaganda" and making "inciting statements" that are divisive.
He commented from Ethiopia, where an African regional bloc known as IGAD has been trying to broker a cease-fire between the government and opposition.
A December gun battle at the army headquarters in South Sudan's capital, Juba, touched off the crisis. President Salva Kiir accused Machar of attempting a coup, a charge Machar denied.
A senior United Nations human rights official Monday said "thousands" of people had been killed in South Sudan's violence. Assistant Secretary-General for Human Rights Ivan Simonovic commented a week after visiting South Sudan, where he said there was evidence of summary executions, the use of child soldiers, sexual violence and other abuses.
He said both sides were guilty of human rights violations.
Bor, the capital of Jonglei state, has been the scene of some of the country's worst violence since the unrest began.