First few paragraphs:

JUBA, South Sudan (AP) — South Sudan’s main opposition party said its leader Riek Machar has been arrested as the U.N. called on all parties to uphold the 2018 agreement that ended the country’s civil war.

The U.N. had warned on Monday that the country was teetering on the edge of a renewed civil war after fighting in the north between an armed group allied to Machar and government forces.

Machar was “in confinement by the government” and his life was “at risk,” opposition spokesperson Pal Mai Deng said in a video address to the media Wednesday night.

The head of the U.N mission in South Sudan, Nicholas Haysom, said following reports of the detention of Machar, all parties should “exercise restraint and uphold the Revitalized Peace Agreement.”

South Sudan’s five-year civil war, in which 400,000 people were killed, ended in a 2018 peace agreement that brought President Salva Kiir and Machar together in a unity government.