A South Sudanese businessman and former intelligence officer says he has launched a new rebel group and intends to overthrow what he calls the corrupt leadership of the country.
The government has not yet commented.
Kerbino Wol has called it the Seventh of October Movement – a reference to the day of a riot at the detention facility where he was held without trial for two years.
He was pardoned by President Salva Kiir in January.
Despite the formation of a unity government after almost six years of civil war, correspondents say South Sudan remains fragile.
Political rivalries have not been resolved and ethnic clashes have increased.
