A U.N. prosecutor investigating atrocities in Darfur has uncovered evidence of a coordinated campaign of vicious attacks in western Sudan. The probe has encountered numerous obstacles, including a lack of access to the region.

International Criminal Court (ICC) prosecutor Luis Moreno Ocampo says he is investigating an ongoing series of killings, rapes and other atrocities in Sudan's Darfur region. But in remarks to the Security Council, the Argentine prosecutor said poor security in Darfur and lack of cooperation by the Khartoum government are preventing investigators from getting a first-hand look at conditions there.

"The continuing insecurities in Darfur do not allow for an effective system of victim and witness protection. This has forced my office to investigate outside Darfur, and represents a serious impediment to the conduct of effective investigations in Darfur by national judicial bodies as well," he said.

In a later closed-door meeting with Council ambassadors, Mr. Moreno Ocampo said he was examining evidence that seems to indicate a coordinated pattern to the attacks in Darfur, which the United States has labeled genocide. The Security Council president, British Ambassador Emir Jones-Parry, said the prosecutor is attempting to determine who is responsible for ordering the atrocities.

"What the prosecutor told us was that the nature of attacks in Darfur demonstrated a degree of coordination, a degree of strategic operation, which implied that someone was in command and control of that operation. His intention is to ascertain who it was, and hold them responsible," he noted.

In a written report to the Council this week, Mr. Moreno Ocampo expressed some hope in future cooperation with Sudan's government. But in an interview with the Reuters news agency, Sudan's justice minister said the International Criminal Court prosecutor would not be granted access to Darfur.

Ambassador Jones-Parry said the Council would insist on full cooperation from Khartoum.

"We will judge government of Sudan by its actions," he added.  "If it becomes apparent the prosecutor is not receiving cooperation, then the Council will have a report from the prosecutor and we will need to respond to that."

Civil war broke out in Darfur nearly three years ago when rebel groups launched an insurrection to protest what they claim was unjust treatment of black African tribes by the Sudanese government. Khartoum responded by unleashing pro-Arab militias known as Janjaweed, who have been blamed for widespread violations of human rights.

Human Rights Watch this week issued a report alleging that senior Sudanese officials were responsible for systematic abuses in Darfur.

The Sudanese government, however, has denied supporting the Janjaweed militias, and vowed to prosecute war criminals internally.