The trial of 25 people accused of being part of the M23 group began Wednesday in DR Congo, some two and a half years after the rebels began seizing large parts of the east of the country.
Only five defendants were present when the trial began in a military court in Democratic Republic of Congo (DRC) capital Kinshasa.
The main defendant, former DRC electoral commission president Corneille Nangaa, is currently on the run.
Nangaa announced in December in Nairobi the creation of a political-military movement the AFC, or Alliance Fleuve Congo, an alliance of rebel groups including the M23.
The justice ministry announced on Monday the opening of the "trial of Corneille Nangaa and his accomplices".
"This trial is part of terrorist activities, war crimes and high treason perpetrated in the eastern part of the DRC," the statement said.
If convicted, they could face the death penalty.
The defence requested an adjournment of the trial after the first suspect was questioned to allow lawyers time to read their client's files.
"The time we are given is very short, in such a serious case, in which some defendants risk the death penalty," said one of the defence lawyers, Clement Muza Kayembe.
The lawyer also spoke out about the presence of Justice Minister Constant Mutamba at the trial.
"In which country have you seen a justice minister go to hearings?" he told AFP.
"It's a moral pressure," he said, asking for "equitable and not fanciful justice" for the defendants.
The list of defendants contains some of the best-known figures of the Rwanda-backed M23, including the group's president Bertrand Bisimwa, its military leader Sultani Makenga and spokespersons Willy Ngoma and Lawrence Kanyuka.
Other people included on the list include members of the People's Party for Reconstruction and Democracy (PPRD) who joined the AFC.
The PPRD is the party of former President Joseph Kabila, who was in power from 2001 to 2019.
Those not present at the trial will be judged in their absence.
The Congolese authorities accuse Nangaa of being behind the bombing of a displaced persons camp last May that killed 35 people.
The trial is set to resume Thursday.
The M23 ("March 23 Movement") took up arms again at the end of 2021 and seized, with the help of the Rwandan army, large swathes of the North Kivu province.