South Sudan opposition says its leader Machar has been arrested

South Sudan’s president Salva Kiir, left, and vice-president Riek Machar (AP/Sam Mednick)

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

The UN 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 Mr Machar and government forces.