'Army fighting against army' in South Sudan
5 January 2014 Last updated at 14:54 GMT
Fighting is continuing in the eastern part of South Sudan, as talks between the country's warring parties are set to resume.
The BBC's Alastair Leithead, who is with government troops outside the strategic city of Bor, said there had been heavy fighting.
He said the fighting essentially involved two trained armies, as the rebel forces included former army units.