The U.N. said it had uncovered a mass grave with 34 bodies in South Sudan on Tuesday, as deadly ethnic and political-fueled fighting in the world's youngest country continued into its second week.

Fighting broke out in the capital Juba on Dec. 15 between troops loyal to President Salva Kiir, from the majority Dinka tribe, and supporters of ousted former vice president Riek Machar, from the Neur tribe. Both men had been leaders of rival factions in the Sudan People's Liberation Army (SPLA), which waged a decades long independence struggle against Sudan. Machar is on the run after Kiir accused him of plotting a failed coup.

The U.N. reported that the mass grave was found in Bentiu, in the north of the country. Earlier estimates put the number of dead at 75, but the U.N. later revised the number of victims down to 34. UNHCR spokesperson Ravina Shamdasani said the victims appeared to be Dinka soldiers from the SPLA.

The U.N. has not confirmed claims of two more sites of mass graves, according to the BBC. A Sudanese man in Juba told AFP that he was one of 12 people to survive after soldiers rounded up 250 people last week, brought them to a police station, and then shot at them. The man reported that they were targeted for being members of the Neur tribe.

Reports have been difficult to corroborate. Foreign journalists have begun arriving in the country, and have begun to complain of government pressure.