Juba, South Sudan – The detention of South Sudan's First Vice-President, Riek Machar, has effectively shattered the 2018 peace deal that brought an end to the country’s five-year civil war, according to Machar’s party, the Sudan People's Liberation Movement In Opposition (SPLM/IO).

Late Wednesday, an armed convoy led by senior security officials, including South Sudan’s defense minister, entered Machar's residence in the capital, Juba. The officers disarmed his bodyguards, and Machar was taken into custody alongside his wife, Angelina Teny, who serves as the country's interior minister.

SPLM/IO deputy leader Oyet Nathaniel Pierino condemned the detention, stating, "The arrest and detention of H.E Dr. Riek Machar effectively brings the peace agreement to a collapse." He added that the country’s prospects for peace and stability were now gravely endangered.

The South Sudanese government has yet to publicly comment on the reported house-arrest of Machar and his wife. However, President Salva Kiir addressed religious leaders on Wednesday, assuring them that he would "never return the country to war."

The United Nations has expressed grave concerns that the country is on the brink of another civil war following weeks of escalating tensions between Machar and Kiir. The two leaders had agreed in August 2018 to end the conflict that had claimed nearly 400,000 lives, but their relationship has since deteriorated amid deepening ethnic divisions and ongoing violence.

In a Thursday press conference, Pierino warned that Machar’s detention had “abrogated” the fragile peace deal, adding that the situation now posed a serious threat to the nation’s future. “The prospect for peace and stability in South Sudan has now been put into serious jeopardy,” he declared.

The UN Mission in South Sudan (UNMISS) echoed Pierino's concerns, stating that the country’s leaders "stand on the brink of relapsing into widespread conflict." The mission further cautioned that any violations of the 2018 peace agreement would have devastating consequences, not only for South Sudan but for the entire region.

Tensions remain high in Juba, where a heavy military presence has been reported around Machar’s home. One local resident told AFP, "There is a high chance of full-scale war, but it will be more deadly and more violent because of the need for revenge." However, Pierino urged SPLM/IO members and the public to remain calm, while diplomatic efforts continue to resolve the situation.

Reath Muoch Tang, the party’s chairman of the foreign relations committee, stated that Machar was under house arrest but initially faced an attempt to be forcibly taken away by security officials. He called the actions a "blatant violation of the constitution and the Revitalized Peace Agreement," and said an arrest warrant had been presented without clear charges.

In response to the escalating crisis, the British and US embassies have scaled down their diplomatic staff and urged citizens to leave the country. The Norwegian and German embassies have temporarily closed their operations in Juba.

The US government has called for Machar’s release, urging President Kiir to show a renewed commitment to peace. The US Bureau of African Affairs tweeted, "We urge President Kiir to reverse this action and prevent further escalation of the situation."

The growing tensions come amid renewed clashes between forces loyal to the two rival leaders in the northern town of Nasir, located in the oil-rich Upper Nile State, further underscoring the risk of a return to full-scale violence.

As the situation in South Sudan remains volatile, the international community is watching closely, with hopes that diplomatic intervention can prevent the country from descending back into war.