South Sudan became independent in 2011
South Sudan became independent in 2011 AFP

South Sudan security forces were investigating Friday a shootout at the home of the troubled nation's powerful former spy chief Akol Koor, who was sacked almost two months ago amid rumours of a coup plot.

Gunfire erupted on Thursday evening in Juba, the capital of the world's youngest country that is plagued by power struggles, ethnic infighting and a deep economic malaise.

The shooting around the home of Koor, who was fired by President Salva Kiir in early October and then placed under house arrest, lasted about an hour, according to an AFP journalist.

There was a heavy deployment of military forces around his home in the Thongpiny district on Friday, an AFP correspondent said, but traffic has resumed and people are going about their daily business.

The Sudans Post newspaper had cited a military source as saying Koor had been arrested after intense fighting that reportedly left dozens of his soldiers dead or wounded.

But South Sudan People's Defence Forces (SSPDF) spokesman Lul Ruai Koang told AFP that "he remains at his house", denying claims circulating on social media that Koor had fled to the UN compound in Juba.

Police spokesman John Kassara said the situation was now calm but that Thongpiny remained sealed off and residents "should remain vigilant".

In an alert to its staff on the ground on Thursday, the United Nations in South Sudan had said the shooting was linked to the arrest of the former spymaster and advised people to take cover.

Koor became head of the feared National Security Services (NSS) after South Sudan's independence in 2011 but was sacked in October leading to widespread speculation he had been planning to overthrow Kiir.

Koang had said on Thursday the shooting involved "our own security forces that had been deployed there to provide extra security".

He said there was a "misunderstanding" between two levels of security providing protection at Koor's home.

"We do not know what had happened and that misunderstanding degenerated into gunfire," Koang said, adding that two servicemen were shot and wounded in the fighting before the situation was contained.

Koor's sacking came just two weeks after the government again postponed by two years, to December 2026, the first elections in the nation's history.

The delay has exasperated the international community, which has been pressing the country's leaders to complete a transitional process, including unifying rival armed forces and drawing up a constitution.

South Sudan has struggled to recover from a brutal civil war between forces loyal to Kiir and his now deputy Riek Machar from 2013 to 2018 that killed about 400,000 people and drove millions from their homes.

It remains one of the poorest and most corrupt countries on the planet and continues to be plagued by chronic instability and climate disasters.