BERLIN (AP) — The United Nations says its staff have found a mass grave in South Sudan's oil rich Unity State.

The U.N. human rights office says staff who visited the site Monday in the northern town of Bentiu counted 14 bodies in the grave and 20 more at a nearby river.

A spokeswoman for the Geneva-based office told The Associated Press on Tuesday that the bodies are among 75 ethnic Dinka who were reported to the U.N. as "unaccounted for and feared dead."

Spokeswoman Ravina Shamdasani said the victims were reportedly members of the Sudan People's Liberation Army.

She said there are unconfirmed reports of least two more mass graves in Jebel-Kujur and Newside, near Juba, the capital.

Shamdasani had initially said they had discovered 75 bodies, but later revised that account.