After days of fighting between rival factions in South Sudan's army, the world's youngest state finds itself at its most dangerous juncture since declaring independence from Khartoum in 2011.

This week's clashes, which have left more than 60 people dead and hundreds wounded, followed what the government claims was an attempted coup in the capital, Juba, on Sunday night. There are fears the unrest could trigger a wider ethnic conflagration in a nation awash with guns and still fragile after decades of war that led to its secession two years ago.

The violence that erupted at the weekend springs from a long-running power struggle between South Sudan's president, former guerrilla commander Salva Kiir, and Riek Machar, another former rebel commander whom Kiir sacked from his post as vice-president earlier this year.

It was apparently sparked when rumours that Machar, who is from the Nuer ethnic group, had been detained prompted a confrontation between Nuer members of the presidential guard and their fellow soldiers from the more populous Dinka tribe, to which Kiir belongs.

Heavy weaponry
The fighting since has included the use of heavy weaponry including tanks. UN officials in Juba say more than 13,000 people have sought refuge in and around two UN bases in the city. "The situation is far from under control," says Dan Eiffe, a former priest from Ratoath, Co Meath, who has lived in South Sudan for decades and now works for the UN.

Kiir, who appeared on state TV this week wearing, significantly, military fatigues instead of his trademark black suit and cowboy hat, accused Machar of trying to seize power and denounced him as a “prophet of doom”.

Some in Juba, particularly those who are uneasy over what they see as Kiir’s drift towards authoritarianism, question the president’s claim of an aborted coup. They accuse him of using it as a pretext to crack down on his rivals, of whom Machar is the most prominent.

Yesterday the government announced that 10 people, including six former ministers, had been arrested in connection with the alleged coup, and five, including Machar, remained “at large”.

When I met Machar last month in Juba, the man who is now among South Sudan’s most wanted was frank not just in his criticisms of the slow pace of progress as the fledgling nation struggles to build itself from scratch, but also his own presidential ambitions.

Sitting under a baobab tree in his central Juba compound, which has reportedly come under RPG and tank fire in recent days, Machar argued that Kiir’s government had failed to harness South Sudan’s potential.

The oil-rich country languishes near the bottom of every development index and lacks basic infrastructure.

Two years after independence, 50 per cent of the population live below the poverty line. Life expectancy is 42 years.

Machar blamed the country’s woes partly on the challenges of transforming the ruling Sudan People’s Liberation Movement (SPLM) – which Kiir has led since 2005 – from the guerrilla force of the past into a political entity befitting the country’s democratic trajectory.

“We are going through a very unpredictable period, the most unpredictable since independence,” Machar said, as baby goats nudged his feet.

“We are due for elections [in 2015] but some have doubts the elections will be held, some have concerns over whether the elections will be free and fair, some have concerns over whether they will be peaceful.”

He said relations between himself and Kiir had become “very strained”.

Asked if he thought Kiir may fear him and his ambitions, Machar replied: “He should not be afraid of me because I am not planning anything secretly. I am simply voicing my views and I have done that in front of him.

“I am not a provocative person, but I am open and transparent about issues. What I see, I say it.

“ Frankly, I feel the current president has done his part, he has steered us through the implementation of the [2005] peace agreement and now through the transition. It will be 10 years by 2015 – he will be the hero of this country.

He doesn’t need to go beyond that.”

Machar had a long list of complaints. “Since independence, we have not been fighting corruption properly; we have not been fighting tribalism; we have not been addressing insecurity in the rural areas and even in the capital itself.”

He did not mince his words when talking of the SPLM: “Our party is not organised, instead it is dysfunctional. The SPLM has lost direction and vision.”

Despite his chequered past – Machar’s history of changing sides during the war means some in South Sudan still view him with distrust – he claimed he would be a shoo-in for the presidency.

'Economic tiger'
"This country needs a new leadership to unite and reconcile it and I think that is me. If I were to run for president tomorrow, I would get an overwhelming majority," he said. "I would build a strong SPLM. I would bring development for this country. I want South Sudan to be an African economic tiger in 10 years. We have massive resources that are going to waste."

Such frankness raised tensions within the SPLM earlier this year, with Machar’s critics suspecting he was becoming too powerful.

When Kiir removed him from the government in July without giving a clear explanation, Machar called on his supporters not to resort to violence in response, warning that Kiir might use it as an excuse to declare a state of emergency.

I asked Machar last month if his power struggle with Kiir could yet turn violent. “It could have been [in July] but I controlled it. We have a local expression: it was like somebody holding the horns of a buffalo. It was difficult.

“We have gone through over 50 years of warfare, why would we resort to political violence now when violence was imposed on us for decades? The people don’t want violence. They hate it because of the past.”

In hiding
It is impossible to know how the events of the past days may have changed the calculations of Machar, who is now in hiding and has made no public statements since the fighting erupted. He risks arrest, and possibly even death after being accused of plotting a coup.

Last month, even as Machar detailed how unpredictable the situation in South Sudan had become, he remained optimistic. “Our country has been through a lot, we will overcome these challenges as we did others before.”

The coming days and weeks are likely to prove the toughest test South Sudan has faced in its young history.

This report was supported with a grant from the Simon Cumbers Media Fund.