World

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.

The BBC outlines the background to South Sudan's crisis - in 60 seconds.

Machar is backed by army deserters, believed to number at least 10,000, and militias from his Nuer ethnic group.

Kiir comes from South Sudan's largest ethnic group, the Dinka.

However, both leaders have influential backers in the other group, even though the conflict has often taken an ethnic dimension.

Our reporter says he heard explosions and saw plumes of smoke coming out of a rebel-held military base on the road to Bentiu.

It seems the rebels are destroying ammunition as they withdraw from the frontline, to prevent it from falling into the hands of advancing government troops, he adds.

Kiir's forces are believed to be about 25 kilometres (16 miles) from Bentiu, capital of Unity state.

The state is rich in oil, the main foreign exchange earner of South Sudan.

Oil production has dropped by 20% since the conflict started.

Civilians from the Nuer community have been streaming into the UN base in recent days, unlike a few weeks ago when the rebel seizure of Bentiu led to Dinkas taking refuge at the base, our correspondent says.

The base is now split into three, with a section for each of the two groups and a third for foreign nationals, he adds.

Bentiu and Bor, the capital of Jonglei state, are the two main centres under rebel control.

Fighting has also been reported around Bor.

On Wednesday, the International Committee of the Red Cross (ICRC) said the humanitarian situation in South Sudan is dire.

'South Sudan is facing a serious crisis that comes on top of a situation that was already difficult,' ICRC president Peter Maurer said, at the end of a three-day visit to the country.

'It is unquestionable that the needs are dire, but their full scope is unknown,' Maurer added in a statement.

South Sudan is the world's newest state.

It became independent in 2011 after seceding from Sudan. (BBC)