A South Sudan general has been killed alongside dozens of soldiers after a United Nations helicopter was attacked as it attempted to evacuate them on Friday, according to the Sudanese government on Saturday.

The UN helicopter was attacked following intense armed clashes between national armed forces and the "White Army", a militia that South Sudanese President Salva Kiir claims are loyal to his vice-president Riek Machar, a rival of his.

In a national address, President Kiir said that his vice-president told him and a UN representative that General Majur Dak would be safe and the evacuation mission would be granted safe passage to Nasir.

The Head of the UN mission in South Sudan, Nicholas Haysom, called the attack "utterly abhorrent" and said it could constitute a war crime that threatens to shake an already fragile peace process.

“We also regret the killing of those that we were attempting to extract, particularly when assurances of safe passage had been received. UNMISS (UN Mission In South Sudan) urges an investigation to determine those responsible and hold them accountable,”  added

“I have said it time and again that our country will not go back to war. Let no one take law into their hands," the South Sudanese President said, adding, “The government which I lead will handle this crisis. We will remain steadfast in the path of peace."

South Sudan ended its five-year-long civil war in 2018 with a power-sharing agreement between President Salva Kiir and Vice President Riek Machar, however, allies to the president are accusing the Machar of creating unrest in Nasir county through the White Army, a group of armed youths from the same ethnic group as the VP.