South Sudan's pro-Machar rebels bolster Bentiu defences

He saw rebels bring a tanker into the city in the oil-rich area, as the frontline moves closer, Alistair Leithead reports.Thousands of people are taking refuge at a UN base on Bentiu's outskirts.At least 1,000 people have been killed in fighting since 15 December.Regionally-brokered talks to declare a ceasefire have stalled.

The conflict erupted after President Salva Kiir accused his ex-deputy, Riek Machar, of plotting a coup - a charge he strongly denied.