South Sudan President Salva Kiir has replaced Vice-President and rival Riek Machar, a move that could potentially undermine last year’s peace deal and reignite war in Africa’s youngest nation.

According to a decree “for the appointment of the first vice-president of the republic of South Sudan”, read on the country’s national broadcaster, Mr Kiir said he had appointed Taban Deng Gai to the post.

The replacement of Mr Machar, a former rebel leader, with Mr Gai — on the recommendation of the group Mr Machar heads — confirmed signs of serious divisions within the Opposition.

Forces loyal to Mr Machar engaged in clashes with Government forces in Juba in early July.

At the time, UN secretary-general Ban Ki-moon said the renewed fighting was “outrageous”

Mr Marchar has not been seen in the capital, Juba, since the clashes, and has accused the President of trying to have him killed.

Mr Gai has been acting vice-president in his absence.