Juba - The trial opened on Tuesday of four top South Sudanese leaders accused of treason for allegedly attempting to topple President Salva Kiir after fighting broke out in December.
The four are Pagan Amum, former secretary general of the ruling party, ex-national security minister Oyai Deng Ajak, former ambassador to the US Ezekiel Lol Gatkuoth, and ex-deputy defence minister Majak D'Agoot.
The four, who spoke in the Juba court only to confirm their names but who have in the past denied all charges, were dressed in suits and appeared to be in good health.
The four were read 11 charges, including the main charge of treason, defence lawyer Ajo Noel said.
"It is too early for us to tell what the case will be," Noel told AFP.
"We want to go through all that the judges will say, and we will see what comes out of it."
The courtroom, which was crowded with spectators including foreign diplomats, was surrounded by armed security officers.
South Sudan's government has been at war with rebel groups since 15 December, when a clash between troops loyal to Kiir and those loyal to sacked vice president Riek Machar snowballed into full-scale fighting across the world's newest nation.
Thousands of people have been killed in the conflict.
Eleven ex-officials were arrested, while Machar - who denied any coup plot - fled.
However, seven of those initially arrested were released without charge in Kenya in January.
Kenyan President Uhuru Kenyatta on Tuesday called for the release of the four men on trial, saying that the regional East African IGAD-bloc - which is mediating peace talks - wanted to find "a political solution to the crisis".
The release of all the prisoners has been a key demand of the rebels.
The two sides signed a ceasefire agreement on 23 January, but heavy fighting has continued.
Stalled peace talks in neighbouring Ethiopia, which have made little progress, are due to resume on 20 March.
"The process is going very slow, but it is going in the right direction," Ethiopian Prime Minister Hailemariam Desalegn said in Addis Ababa Tuesday, after meeting with Kenyatta.
Over 930 000 civilians have fled their homes since fighting began, including over quarter of million leaving for neighbouring nations as refugees, according to the United Nations.
War crimes have been committed by all sides in the war, Human Rights Watch has warned, detailing widespread atrocities in almost three months of carnage.
Some key towns swapped hands several times, as rebels and government troops battled for control.
Over 75 000 civilians are still crammed into UN peacekeeping bases in fear of revenge attacks, with conditions becoming increasingly squalid as weeks drag into months and the heavy rains start.
The trial continues on Wednesday.