Darfur: the genocide continues: more than 200,000 people have been killed and 2.5 million displaced during three years of ethnic conflict in Darfur. Now, the violence is spreading and threatening the stability of neighboring countries.

Death is no stranger in Tawila, Sudan, where thousands of Darfurians are crowded into a sprawling, makeshift refugee camp. Malaria and diarrhea course through the camp, picking off the children first, then the elderly. And the conflict between black Africans and government-backed Arab militiamen called janjaweed drives more people into the camp every day.

Mariam Ibrahim Omar recently buried her 21-month-old son, Ismail, in a graveyard near the camp. When he became ill with a high fever, she carried him on her back to a clinic run by an aid organization. But the doors were locked, the doctors and nurses long gone. The lone aid organization still operating in Tawila was the United Nations World Food Program.

Since 2003, more than 200,000 civilians have been killed in Darfur--a vast, arid region of western Sudan. Another 2.5 million people have been displaced and are living in refugee camps, mostly in Chad. President Bush is among many in the international community who have denounced the slaughter as genocide.

The conflict pits Arab Africans against black Africans. (Both groups are Muslim.) It started in 2003, when rebels began demanding greater political and economic rights for black Darfurians from the Arab-dominated Sudanese government in Khartoum. The government responded by turning loose the janjaweed. On horses and camels, these armed militiamen continue to storm into black villages, torching houses, stealing cattle, destroying crops, and raping and killing villagers.

HUMANITARIAN CRISIS 

The war in Darfur has led to what the U.N. has called the "world's worst humanitarian crisis." Over the past year, the conflict has spread into Chad, and hundreds of thousands of Chadians have become refugees in their own country. In the refugee camps, people are dying because they cannot get medical care, clean water, or enough food.

Relief organizations are trying to prevent these deaths, but their ranks and resources are shrinking. The World Food Program says that a shortage of money is forcing it to cut in half the amount of food it distributes to Darfur refugees. Many countries have not sent the money they have pledged; the U.S. says it is supplying 85 percent of the food aid going to Darfur.

The Darfur crisis also affects the stability of neighboring countries. Chad accuses Sudan of backing rebels who have tried to overthrow its government, while Sudan claims that Chad backs anti-government rebels in Darfur. Violence is also spilling over into the Central African Republic.

KEEPING THE U.N. OUT

In May 2006, the Sudanese government and the largest of the Darfur rebel groups signed a peace agreement. A cease-fire was to take effect, and the janjaweed and rebel forces were to disarm. But new battles broke out, as rebel factions turned on each other.

The U.S. has pressed President Omar al-Bashir to let U.N. peacekeepers into Darfur since the 7,000 African Union troops already there are not able to provide adequate security. But the government, which continues to deny hacking the janjaweed, refuses to let the U.N. in.

In Khartoum, the picture is quite different. Money from the country's oil boom is very much on display with office towers rising and wealthy Sudanese filling the cafes, even as people are dying 600 miles away in Darfur.

Oil's influence also helps explain the lack of a stronger U.N. response. Security Council diplomats say that action against Sudan, including sanctions, is being resisted by China, which buys Sudan's oil; Russia, which has helped Sudan develop its oil industry and has sold weapons to the government, and Qatar, the Council's Arab representative.

Sudanese officials have placed tight restrictions on relief organizations, and aid workers are increasingly vulnerable to attack. On December 9, gunmen on horseback ambushed a truck carrying medicine and aid in Darfur, killing about 30 civilians; some of them were burned alive.

"The situation for humanitarian workers and the United Nations has never been as bad as it is now," says an aid official. "The space for us to work is just getting smaller and smaller."

By Lydia Polgreen in Sudan

Lydia Polgreen is the Dakar, Senegal, bureau chief for The New York Times; additional reporting by Jeffrey Gettleman and Warren Hoge of The Times.