DHAKA: UN chief Ban Ki-moon has urged the Security Council to add 5,500 UN troops to the 7,000-strong force in South Sudan, amid escalating fighting there.
His plea comes as new details emerge of alleged ethnic killings committed during more than a week of violence, reports BBC.
Ban warned that anyone responsible for abuse would be held to account.
Tens of thousands of people have fled fighting, as rebels thought to support sacked former vice-president Riek Machar have seized major towns.
A journalist in the capital Juba, Hannah McNeish, said witnesses had told her about a massacre in which more than 200 people, mostly from the Nuer ethnic group, were herded into a police station and shot by security forces.
Another man interviewed at the UN base in Juba reported that gunmen from the Dinka tribe were shooting people in Nuer districts who did not speak the Dinka language.
Ban Ki-moon: "The world is watching all sides in South Sudan"
The allegations cannot be independently verified.
Up to 1,000 people are thought to have been killed in the fighting and UN compounds are sheltering more than 40,000 civilians.
UN humanitarian co-ordinator Toby Lanzer, who was in Bor, north of Juba, over the weekend, told the BBC he had witnessed "some of the most horrible things that one can imagine".
He said people "were being lined up and executed in a summary fashion".
BDST: 1214 HRS, DEC 24, 2013
RS