Thousands dead in South Sudan violence, UN says

Thousands of people must have been killed in the past week of violence in South Sudan, the top UN humanitarian co-ordinator there has told the BBC.

Toby Lanzer, who is in Bentiu in northern Unity state, said it had been 'a devastating week for South Sudan'.

Earlier President Salva Kiir said his forces had recaptured the key town of Bor days after it was seized by rebels.

The rebels are led by Riek Machar, of the ethnic Nuer, who has been battling President Kiir, of the Dinka.

The UN earlier said that it had reports of at least three mass graves.

One was in Bentiu in the north, and two in the capital, Juba.