South Sudan President Salva Kiir on Tuesday fired all ministers and deputy ministers, according to a decree on state-television, dpa reported.
Vice President Riek Machar Teny was also sacked.
No replacements were made for the fired officials. The number of ministries was also reduced from 29 to 18.
No reason was given for the decree.
Kiir ordered ministries to be run by their directors until further notice.
At the level of the ruling party, Kiir also ordered an investigation into SPLM secretary general Pagan Amum Okiech.