Growing pains? South Sudan's president fires entire cabinet

South Sudanese President Salva Kiir has fired his entire cabinet and vice president in the 2-year-old nation's biggest political shake-up thus far.

Kiir issued a presidential decree announcing the reshuffle during talks to defuse tensions with Sudan, according to state media reports cited by the New York Times.

Among those removed from their posts were Pagan Amum, the secretary-general of the ruling party, the Sudan People's Liberation Movement (SPLM). Amum was the top negotiator at long-running peace talks that eventually gave South Sudan its autonomy from Sudan.

Vice president Riek Machar was also removed.

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While no clear reason was given for the sackings, the BBC cited analysts as saying that Kiir and Machar had been embroiled in a power struggle for months.

There were suggestions that Machar, already stripped of some of his powers in April, might stand against Kiir for leadership of the SPLM before the presidential election in 2015.

The BBC also wrote that Kiir had also been battling to maintain control of the SPLM, the former rebel group that now runs the country. Many of the ministers sacked were key figures in the SPLM's armed wing, which led the 1983-2005 war against the Sudanese government in Khartoum.

The announcement sparked concern among diplomats about stability in the fledgling nation. 

Embassies issued warnings to citizens to take care. The United Kingdom's Foreign Office said its nationals should "remain at home or in another safe place," warning: "It is possible that this move could lead to increased political tension or disturbances in Juba [South Sudan's capital] and other parts of the country."

However, Barnaba Marial Benjamin — until his suspension on Tuesday, South Sudan's information minister and government spokesman — dismissed the concerns, telling Agence France-Presse: "Why should there be instability? This is a constitutional position... he (Kiir) is the head of the government."

Under-secretaries will run the government departments until new ministers are appointed, according to the BBC

Since the 2011 referendum in which South Sudanese voted overwhelmingly to split from the north, the south has suffered from chronic economic problems.