South Sudan generals and dozens of soldiers were killed after a UN helicopter attempted to evacuate them from the town north of Nasir, the government said.
The UN said Friday's incident, which could hit the already vulnerable peace process, was “completely abominable” and could be a war crime.
The power shearing agreement between President Salva Kir and First Vice President Riek Machar has been threatened in recent weeks by clashes between allied forces in the northeastern Nile River Province.
The UN crew were trying to airlift their soldiers after a violent clash at Nasir and a so-called white man, a militia tied to an army loyal to his bitter rival, Machar.
In a national speech announcing the deaths of General Majur Dak and other soldiers, Kiel said that Makar assured him and the UN representatives were safe and that rescue missions should fly to Nasir to evacuate him and his men.
Kiel urged the citizens to stay calm, saying: Don't get the law.
“My government will deal with this crisis. We will maintain a solid path of peace,” he added.
Information Minister Michael McQueuy said that “about 27” troops had been killed. The UN crew was among the dead.
It was not immediately clear whether the helicopter hit as if it were in the air or if the attack occurred when it was still on the ground.
South Sudan, the youngest country in the world, ended its five-year civil war in 2018 with a power sharing agreement between KIIR and Machar.
However, Kiel's allies accused him of hindering Micher's strengths in Nasir County. This is in a league with White Army, a loose band of armed youths from the area of the same ethnic Nua community as the Vice President.
Both Baluang, a spokesman for Machar, declined to comment on the attack. Machar's party has previously denied involvement in recent battles at Nasir.
Nicholas Haysom, head of the United Nations Mission in South Sudan (UNMISS), said the attack was “absolutely abomination” and could constitute a war crime under international law.
“We also regret the murder of the people we were trying to extract, especially when guarantees of safe passage are received. Unmiss will urge investigations to determine who is responsible and hold them accountable,” he said.
A Machar spokesman said earlier this week that security forces arrested the Minister of Oil, Minister of Peacebuilding, Deputy Secretary of the Army, and other senior officials allied with Macher, putting the 2018 peace agreement at risk, which would end the civil war between Kier and Machar forces.
According to a Machar spokesman, the government has not commented on detention and with the exception of the Minister of Peacebuilding, all officials detained remain in detention or house arrest.
The whites fought alongside the Machar army in the 2013-18 civil war.
Analysts warn that escalating tensions could lead to full-scale conflict. “South Sudan is rapidly sliding into a full-scale war,” said Alan Boswell, Africa's horn director for International Crisis Group.
He urged the UN to prepare peacekeepers to save civilian lives, adding that “we fear a massive ethnic massacre if the situation is not included anytime soon.”
In a statement, the UN “urged all actors to refrain from further violence and urgently intervene to ensure that the country's leaders resolve tensions through dialogue and that the security situation in Nasir will not deteriorate.”
South Sudan's UN mission was established shortly after it gained independence from Sudan in 2011. Approximately 20,000 peacekeeping forces from 73 countries serve there.
Reuters and the Agency France Press contributed to this story
