US aircraft attacked, fighting escalates in South Sudan

US aircraft flown into South Sudan to help with evacuation efforts on Saturday came under fire that wounded three US servicemen, officials said, as fighting in the country escalated.

South Sudan’s embattled government said a top army commander in the nation’s key oil-producing region had defected to a fast-growing rebel force made of opponents to President Salva Kiir.

The upsurge in hostilities in the world’s youngest nation, which gained independence from Sudan in 2011, came despite an offer from the president to open talks with his former deputy Riek Machar, who is accused of having started the fighting last week by attempting a coup.

Machar in turn accuses Kiir of conducting a violent purge over the past week, and his loyalists are now fighting the central government on several fronts.

US and Ugandan officials said three US military aircraft that were trying to land at Bor, the rebel-held capital of Jonglei state, were fired on and forced to return to neighbouring Uganda with one of the aircraft hit and leaking fuel.

“Three American officers were injured. The three military helicopters have landed at Entebbe military airbase with the injured officers taken on a C-130 to Nairobi,” a Ugandan official said.

“The injured troops are being treated for their wounds,” the Pentagon also said in a statement.

Military sources identified the aircraft as Ospreys, which are tiltrotor aircraft capable of vertical or short takeoff and landing.

The US operation was part of a major regional effort to evacuate foreign nationals from across the country, officials said. Neighbouring Kenya on Saturday ordered its troops in to evacuate Kenyans stranded in the country and Uganda had also sent in a special forces unit.

At least 500 people have been killed in the capital Juba alone in six days of fighting, while tens of thousands have been displaced — many of them seeking shelter at UN bases amid warnings that the impoverished nation was on the brink of all-out civil war.

In Juba, fresh bursts of gunfire rang out at hourly intervals overnight on Friday, prompting a new wave of terrified citizens to attempt to flee during the day.

Juba’s main bus park was crowded with people struggling to find space on public transport, while foreigners have headed to the airport where several countries — including the United States and Britain — have sent military transport planes to evacuate their nationals.

Fighting has spread to the town of Bor, which lies some 200 kilometres north of Juba and which was seized by rebels during the week. South Sudan’s army spokesman said an operation was underway to retake the town.

“We are moving towards Bor... there is fighting, but we are supported by air units,” Philip Aguer, spokesman for the Sudan People’s Liberation Army (SPLA), said.

Aguer said that in northern oil-producing Unity State, a key commander — Major-General James Koang Choul — appeared to have defected to Machar’s side.

“We have lost contact with the commander... and there are reports he has joined the forces of Riek Machar,” Aguer said, while insisting that government forces were still in control of the area — something the rebels have contested.

Oil companies have been evacuating workers — with Chinese state oil company China National Petroleum Corp (CNPC) confirming it was pulling out its staff.

Oil production accounts for more than 95 per cent of South Sudan’s fledgling economy, with the campaign group Global Witness warning that “if rebel forces were to capture the oil fields, they could effectively hold the government to ransom.”

Neighbouring Sudan has also warned it is concerned over the fate of vital oil flows.

At least five South Sudanese oil workers were killed on Wednesday in Unity state after attackers stormed their compound, with a senior UN official saying they were singled out for their ethnicity.

Two Indian peacekeepers were also killed and one badly wounded on Thursday when attackers stormed a base in Jonglei state, with 36 civilians sheltering in the base also feared to have been killed.

Although the unrest appeared to start as a result of a political spat, the violence has taken on an ethnic dimension pitting Kiir, an ethnic Dinka, against Machar, a Nuer.

South Sudan gained independence from Sudan as part of a peace process after a two-decade civil war that left two million dead, but it has never been able to heal its own ethnic rivalries.

US President Barack Obama has warned that hopes for South Sudan at its independence from Sudan in July 2011 are now “at risk”, amid reports from rights groups of an upsurge in ethnic killings.

US Secretary of State John Kerry said on Friday he was sending Donald Booth, his special envoy for Sudan and South Sudan, to the region to encourage talks between the warring factions.

African ministers have also stepped up pressure on Kiir to start talks with Machar.

United Nations Secretary-General Ban Ki-moon on Friday issued an appeal for an end to hostilities and urged the leaders of Sudan’s warring factions “to resolve their personal differences through dialogue immediately”.