Following recent arrests that heightened the situation, forces loyal to President Salva Kiir released Peacebuilding Minister Stephen Par Kuol, a key ally of First Vice President Riek Machar, according to Machar's spokesman Puok Both Baluang.
However, other Machar allies, including the petroleum minister and a deputy military head, remain in custody. Security forces this week arrested or placed them under house arrest, actions that threaten the existing peace deal established after the civil war.
The recent events followed clashes in the strategic town of Nasir between national forces and the White Army militia, largely composed of Machar's Nuer ethnic group. The White Army previously fought alongside Machar's forces against Kiir's Dinka troops during the 2013-2018 civil war.
While the government has not commented on the detentions, Information Minister Michael Makuei accused Machar's forces of collaborating with the White Army in an attack on a military garrison near Nasir, an allegation that Machar's party denies.