The International Criminal Court has announced its first investigation will look into allegations of serious crimes in the Democratic Republic of Congo.
The inquiry will focus on alleged crimes in the Ituri region
The alleged offences to be investigated include rape, torture and the use of child soldiers in the country.
ICC chief prosecutor Luis Moreno-Ocampo described the move as a "major step forward" for international justice.
The court, which was set up two years ago, is the first permanent body to investigate war crimes.
Prosecutors will investigate the crimes allegedly committed in the country's north-eastern Ituri region, where clashes between Lendu and Hema ethnic militias have claimed about 50,000 lives since 1999.
The trial is expected to take place next year.
"This is an enormous milestone in the struggle to limit impunity from mass killings, widespread rape and ethnic
cleansing," said Richard Dicker of Human Rights Watch.
"The recent killings and rapes in eastern Congo underscore the urgent need for a thorough investigation."
Earlier this month, renegade forces which briefly took control of the eastern town of Bukavu.
DR Congo has recently emerged from a five-year civil war which has been described as the worst conflict since World War II.
Three million died during the war which sucked in at least six other countries, including Rwanda and Uganda who backed rebel groups.
DR Congo is one of more than 90
countries to have ratified the court treaty, although a number of nations, notably the United States, have spurned the court.
On Wednesday, the US gave up trying to win its soldiers immunity from prosecution at the court.
The ICC is restricted to cases which have occurred within the past two years.