Seven South Sudanese rebel leaders face charges of treason over an alleged coup attempt that sparked weeks of fighting, the authorities have said.
Justice Minister Paulino Wanawila said those facing trial included former Vice President Riek Machar, who has not yet been captured.
The government had previously indicated that it might grant an amnesty, after signing a truce last Thursday.
Correspondents say the charges could jeopardise the ceasefire deal.
Mr Wanawila said treason charges would be brought against four men who were already in custody, plus three men on the run.
"If someone violates the law you don't go and torture that person, you prosecute that person according to the law," he said.
The government confirmed that some of those detained after the fighting broke out have been released.
It underscores the animosity between the government of President Salva Kiir and the rebels, many of whom are loyal to Mr Machar.
Although both men have supporters from across South Sudan's ethnic divides, fighting has often been communal, with rebels targeting members of Mr Kiir's Dinka ethnic group and government soldiers attacking Nuers.
Mr Kiir accused Mr Machar and other former officials of attempting a coup after fighting broke out in the capital Juba on 15 December, something Mr Machar denies.
While Mr Machar fled, 11 officials were arrested. Rebels have made their release a condition of any peace deal.
On Wednesday, the government announced that seven of those officials have now been freed and flown to Kenya, but the other four will be put on trial.
The seven men targeted for trial include:
- Riek Machar, whose sacking as Mr Kiir's deputy sparked much of the unrest
- Pagan Amum, former secretary general of the ruling party
- Former National Security Minister Oyai Deng Ajak
- Former ambassador to the US Ezekiel Lol Gatkuoth
- Chief rebel delegate Taban Deng, who signed the ceasefire
Both sides say they are committed to the ceasefire, but there is still fighting in some areas, and the United Nations has described the situation as "fragile".
Aid groups say up to 10,000 people have been killed in the conflict, and more than 500,000 displaced, approximately 76,000 of them sheltering in UN bases.
The UN's aid chief Valerie Amos has wrapped up a three-day visit to the country with a trip to Malakal, where she said some people were afraid to return home despite the truce.
Baroness Amos said the people she spoke to said they had "completely lost faith'' and wanted to be relocated to other parts of South Sudan, or even out of the country.
Fighting erupted in the South Sudan capital, Juba, in mid-December. It followed a political power struggle between President Salva Kiir and his ex-deputy Riek Machar. The squabble has taken on an ethnic dimension as politicians' political bases are often ethnic.
