Prosecutors at the International Criminal Court have named a minister and a militia leader who they suspect of war crimes in Sudan's Darfur region.
More than two million people have been forced to flee their homes
Sudanese Humanitarian Affairs Minister Ahmed Haroun and Janjaweed militia leader Ali Muhammad Ali Abd al-Rahman, also known as Ali Kushayb, were named.
Some 200,000 people have died and more than two million people have fled their homes during the four-year conflict.
Sudan has rejected the charges and said it will not hand over the suspects.
The two are accused of 51 offences, including mass murder, rape and torture.
The alleged crimes occurred during attacks on villages near Kodoom, Bindisi, Mukjar and Arawala in West Darfur.
Speaking in The Hague, where in the International Criminal Court (ICC) is based, chief prosecutor Luis Moreno-Ocampo asked pre-trial judges to issue summonses for the suspects.
He said there was reason to believe they "bear criminal responsibility for crimes against humanity and war crimes" in 2003 and 2004.
The attackers, he said, "did not target any rebel presence. Rather they targeted civilian residents based on the rationale that they were supporters of the rebel forces".
The strategy, Mr Moreno-Ocampo added, "became the justification for the mass murder summary execution and mass rape of civilians who were know not to be participant in any armed conflict".
Mr Haroun, who was interior minister in charge of Darfur at the height of the conflict, is accused of helping to recruit militias.
"Ahmad Haroun visited Darfur on a regular basis and became known to people in Darfur as the official from Khartoum who recruits, staffs and arms the Janjaweed," Mr Moreno-Ocampo said.
"The evidence shows that Ahmad Haroun provided arms for the Janjaweed from a budget that was unlimited and not publicly audited."
Sudanese Justice Minister Mohammed Ali al-Mardi insisted that Mr Haroun had no links with the Janjaweed and said Mr Kushayb was already in detention in Sudan.
The minister also reaffirmed Sudan's contention that the ICC had no jurisdiction to try the suspects.
Human rights groups have also been critical of the investigation, which was conducted mostly outside Sudan owing to security concerns.
Numerous international reports and experts have directly linked the activities of the Janjaweed to the central Sudanese government in Khartoum.
Many villages have been burned down in Darfur
The BBC's Jonah Fisher in Khartoum says joint attacks on villages have been well-documented and there is little doubt the militia have been given weapons and vehicles to fight rebels.
Mr Moreno-Ocampo has spent two years examining evidence gathered by a UN investigative team.
ICC judges now have to decide whether to open an inquiry against the suspects with the aim of issuing international arrest warrants.
The court, set up in 2002, is the world's first permanent tribunal for genocide, crimes against humanity and war crimes.
It is a court of last resort, intervening only when national authorities cannot or will not prosecute.