Tensions are rising in the oil-rich east African nation of South Sudan after Riek Machar who serves as a vice president was arrested in the capital.

Sudan’s army said Wednesday it had recaptured Khartoum’s international airport, and the military chief flew back to the capital for the first time in nearly two years of war, bringing the military closer to regaining full control of the city from the rival Rapid Support Forces paramilitary group.

In dramatic scenes that appear to mark a turning point in nearly two years of civil war, Sudan’s military is driving fighters of its rival, the Rapid Support Forces, out of Khartoum.

When South Sudan declared independence from Sudan in 2011 to a chorus of worldwide congratulations and celebrations, rebel-leader-turned-president Salva Kiir promised his people freedom and democracy.

Two years after the civil war in Sudan erupted, the Sudanese army has stated it was recaptured Khartoum, taking control from the paramilitary group Rapid Support Forces. Army chief Abdul Fattah al-Burhan issued a video on Thursday in which he declared "Khartoum is free".

A New York Times reporter and photographer were the first Western journalists to visit central Khartoum since the civil war broke out two years ago. The scale of how much has been lost was inescapable.

A long-simmering dispute between Sudan’s army and a paramilitary group exploded into a full-blown civil war in April 2023. At least 150,000 people may have been killed since then, according to US estimates,

Mr Machar was "in confinement by the government" and his life was "at risk" after "heavily armed vehicles forcefully entered his residence", the party says.

Russian financial and military contributions have been credited with helping the SAF achieve its gains in recent months. Russia has long desired a Red Sea naval base near Port Sudan, and the expulsion of Russia’s fleet from Syria following the fall of President Bashar Assad increased the importance of such a base.