Security forces in South Sudan have arrested the oil minister and an army general, who are senior members of the main opposition, sparking concerns that the peace deal that ended the civil war may be under threat.

South Sudanese forces have arrested the petroleum minister and several senior military officials allied with First Vice President Riek Machar, Machar's spokesperson said on Wednesday, jeopardising a peace deal that ended a five-year civil war.

South Sudan's top oil and gas official has been arrested at home amid concerns that a peace deal struck in 2018 by long time rivals President Salva Kiir and First Vice President Riek Machar is in danger of unravelling.

Petroleum Minister Puot Kang Chol and General Doup Lam have been arrested, and Vice President Riek Machar's residence surrounded, as troops loyal to South Sudan's President Salva Kiir conduct an apparent crackdown.

South Sudanese soldiers have surrounded Vice President Riek Machar’s home in the capital and several of his allies were arrested after an armed group allied to him overran an army base.

NAIROBI (Reuters) -South Sudanese forces have arrested the petroleum minister and several senior military officials allied with First Vice President Riek Machar, a vice presidential spokesperson said,

South Sudan, the world's youngest country, ended a five-year civil war in 2018 with a power-sharing agreement between bitter rivals President Salva Kiir and his deputy Machar.