New evidence is emerging of alleged ethnic killings committed during more than a week of fighting in South Sudan.
The violence follows a power struggle between President Salva Kiir Mayardit, a Dinka, and his Nuer ex-deputy Riek Machar.
A reporter in the capital, Juba, quoted witnesses as saying more than 200 people, mostly from the Nuer ethnic group, were shot by security forces.
Another man in Juba said gunmen from the majority Dinka ethnic group were shooting people in Nuer areas.
The fighting first erupted in Juba last week and has spread throughout South Sudan, with rebels supporting Riek Machar seizing the major towns of Bor and Bentiu, north of the capital.
Bentiu is the capital of the oil-producing Unity State.
Salva Kiir has accused Riek Machar, who he sacked in July, of plotting a coup. Riek Machar denies he is trying to seize power, while the government has denied it is behind any ethnic violence.
The fear is that the personal rivalry between the former allies will spark a full-scale conflict between the Nuer and Dinka groups.
The official death toll stands at 500, but aid agencies say the true figure is likely to be much higher.
There has also been fighting in Upper Nile State but few details have emerged.
Another 81,000 people have been displaced, the UN’s humanitarian agency says, with about half seeking shelter at UN bases.
President Salva Kiir has said he is willing to hold talks with Riek Machar – and that a delegation of East African foreign ministers had offered to mediate – but that his former deputy would have to come to the table without any conditions.
[youtube 3vtPYuB5mCc 650]