Prosecutors at the International Criminal Court in the Hague have charged two Congolese militia leaders with war crimes.
Germain Katanga and Mathieu Ngudjolo Chui are accused of planning and ordering an attack, in which more than 200 villagers were allegedly killed.
Reports say some of the victims were burned to death, and many women were forced to become sex slaves.
This is only the second case to be launched by the court, set up in 2002. The first trial, of another Congolese militia leader, Thomas Lubanga, has been suspended over concerns that evidence was withheld from the defence.
Mr Lubanga, who was on the other side of the Ituri conflict, may be released over concerns that the defence was denied access to some evidence.
Defence lawyers for Mr Katanga and Mr Ngudjolo have asked judges to suspend the case against them as the prosecution is using the same evidence.
However, the court has decided to go ahead with the hearing, as the proceedings are not as advanced.
A “confirmation of charges” is now set to take place at which evidence will be presented to support the charges, which include war crimes and crimes against humanity. These include murder, sexual slavery, rape, inhumane acts and recruiting child soldiers.
At the end of this process the court will have 60 days in which to decide whether or not to go to trial.
“Over 200 children, women, elderly and civilian men were killed,” in the north-eastern village of Bogoro, said Deputy Prosecutor Fatou Bensouda.
The Ituri conflict, which raged well after a wider peace accord officially ended Congo’s 1998-2003 war, pitted foreign-backed militias from the Hema and Lendu ethnic groups against one another.
Mr Katanga headed the Patriotic Forces of Resistance of Ituri (FRPI), while Mr Ngudjolo led the allied Front of Nationalists and Integrationists (FPI) militia.
The ICC, based in The Hague, was set up in 2002 as the world’s first permanent war crimes court.
It was designed to end the need for various ad hoc war crimes courts – including the chambers created to deal with war crimes committed in the former Yugoslavia and the genocide in Rwanda.