Riek Machar replaced as South Sudan vice-president

South Sudan's President Salva Kiir announced on Monday that former rebel leader Riek Machar had been replaced as vice president, confirming signs of serious divisions within the opposition.

Kiir said he had appointed Taban Deng Gai to the post on the "recommendation of the top leadership of the SPLM/A (IO)" -- the group Machar heads and which engaged in clashes with government forces in Juba in early July.

Last week Machar said he had fired Deng as minister of mines -- a post that was within Machar's powers to appoint.

Riek Machar, pictured in 2015, has accused the president of trying to have him killed ©Zacharias Abubker (AFP/File)

Then around 100 SPLM/A (IO) members came out to name Deng as the movement's leader and by extension the first vice president, because Machar's absence from the capital meant the post was effectively vacant.

Machar has not been seen in Juba since the clashes earlier this month and has accused the president of trying to have him killed.

In reaction to the show of support for Deng, the "political bureau" of the ex-rebel movement said Sunday it condemned "in the strongest terms possible the attempt to destabilise the SPLM/A (IO) and destroy the (2015) peace agreement."

It accused Deng of having a "personal vendetta" against Machar and his supporters of having been "coerced" by the Kiir's camp.

Machar and Kiir fell out in 2013, little more than two years after South Sudan became independent, when Kiir accused his vice president of plotting against him.

The result was a civil war that killed tens of thousands of people.

The latest is a series of peace agreements was sealed in August 2015. Deng was the chief negotiator for the SPLM/A (IO).

Kiir had given Machar a deadline of Saturday to return to Juba.

But Machar has refused to come back until the deployment of a neutral force of African troops -- a plan approved by the African Union but rejected by Kiir.