The International Criminal Court's chief prosecutor has alleged that top Sudanese government officials are behind some of the most heinous crimes committed during the Darfur conflict.

Luis Moreno-Ocampo has yet to name the officials, but in a report for the U.N. Security Council he says "the whole state apparatus" can be linked to crimes against humanity.

The report says senior government officials - working through pro-Khartoum Janjaweed militias - have orchestrated crimes, including the rapes of girls as young as five-years-old.

Sudan's ambassador to the U.N., Abdalmahmoud Abdalhaleem Mohamed, Wednesday called the report "fictitious and vicious."

He accused Moreno-Ocampo of trying to destroy the peace process.

Security Council envoys are in Sudan, trying to resolve tensions that are threatening to derail a 2005 peace agreement between the north and south.

A spokeswoman tells the Associated Press Moreno-Ocampo plans to name the Sudanese officials, and present additional details to a tribunal at The Hague, Netherlands, in the coming weeks.

He is scheduled to address the Security Council on the situation in Darfur Thursday.

In comments to reporters last week, Moreno-Ocampo suggested the officials involved are at a higher level than Sudan's state minister for humanitarian affairs, Ahmed Haroun.

The International Criminal Court issued arrest warrants for Haroun and militia leader Ali Kosheib last year, charging them with 51 counts of war crimes and crimes against humanity, but the Sudanese government has so far ignored warrants for their arrest.

A coalition of human rights groups, known as Justice for Darfur, Wednesday urged the U.N. Security Council to increase pressure on Sudan to surrender the men to The Hague.

Five years of fighting in the region between rebels, the Sudanese government and government-backed militias has displaced some 2.5 million people and killed up to 300,000 others.

Some information for this report was provided by  AP and Reuters.