The United Nations Security Council has called for an immediate investigation into the massacre in the northeastern region of the Democratic Republic of the Congo last week. At the same time, the New York-based International Rescue Committee (IRC) is calling the four-and-one-half-year-old Congo civil war the deadliest conflict in African history.

The United Nations sent an investigative team to look into reports that hundreds, perhaps as many as 1,000, civilians were slaughtered last week in Ituri province, the scene of some of the worst atrocities since the civil war began in 1998. The U.N. investigators found fresh mass graves.

It is not clear who is behind the massacre. Rival ethnic groups signed a cease-fire in March and a transitional government was sworn in Monday. But neighboring nations have supported various factions during the conflict and Uganda still has troops in the Ituri area.

Following a closed meeting on the situation in the DRC, the Security Council said the perpetrators should be identified and brought to justice. The Council president, Mexican Ambassador Adolfo Aguilar Zinser, read the Security Council statement.

"They called on the Ugandan forces to withdraw from the territory of the DRC without delay and recalled that so long as they are deployed on the ground, these forces have the responsibility to ensure the safety of the civilian population," he said.

The Security Council also asked the U.N. Commission on Human Rights to begin an immediate investigation into the massacre.

Meanwhile, the private International Rescue Committee released a survey documenting more than three million deaths in the DRC between August 1998 and November 2002, making it the deadliest conflict since the Second World War and the worst in African history.

Michael Despines, who just returned from six years with the IRC in the Democratic Republic of the Congo, says that while violence accounts for about 12 percent of the deaths, the rest resulted from the deprivation caused by the war.

"Most of that is due to what we are calling the side effects of the war - a breakdown of the economy, a breakdown of the health-care system, malnutrition," he said.

Despite several well-publicized incidents of atrocities, Mr. Despines says the overall situation in the DRC has improved and violence has actually subsided significantly in the last year. But the DRC still has the world's highest mortality rate. The IRC's Michael Despines says the international community must become more active in helping to resolve a range of issues from ethnic differences to land issues to protection of the DRC's rich natural resources, especially diamonds and gold.

"The whole exploitation of natural resources in the Congo is one of the issues that needs to be addressed. It still is fueling much of the conflict that is going on in the Congo," he said.

Mr. Despines went on to says the 5,500 U.N. peacekeepers in the DRC are an inadequate number for a war-torn nation about the size of Western Europe with a population of 50 million. He says the international community must take stronger steps to protect the DRC's resources and borders and support the development of the political process or what he calls the world's "greatest humanitarian crisis" will continue.