One month ago, the body of Sulliman Bashir Nassir, a prominent man from an African tribe, was found slumped in his barn not far from this foul-smelling, overflowing livestock market in the Darfur region of western Sudan.

His killers were Janjaweed, his family said, members of a government-backed Arab militia that has terrorized and raided Darfur for months. The militiamen also took off with the family's hard-earned assets: 800 cows, 450 goats, 20 donkeys and 6 horses, they said.

On a recent day, the local leader of Nassir's tribe, Abdel Sharrifa Gharida Abdel Rhani, drove a Land Rover through the soft sand to the market, searching for the family's animals. He looked for the brand -- a large circle with an X -- that Nassir used to mark his herds. For 40 minutes, he scanned a field packed with more than 5,000 camels and 7,000 head of cattle.

"That's our mark!" he said suddenly, pointing at a cluster of cattle. "These could be them!"

Rhani started snapping photographs and writing notes in a thick folder. But within minutes, an imposing man wielding an ivory-encrusted walking stick marched over to the vehicle. He reached inside and grabbed the wheel. "There is nothing here for you," he boomed at Rhani. "Go. Go."

The human suffering in Darfur is well documented: the burning of villages that has driven 1.5 million Africans off their land and into squalid refugee camps; rapes that have locked the population in fear; and the unpunished killings of tens of thousands of people, most of them men.

But another crime being committed in the region may prove just as difficult to reconcile: the widespread looting of livestock. Stolen animals worth millions of dollars have flooded markets like this one in Nyala, the capital of South Darfur province, according to international organizations and independent Sudanese investigators.

Cows, camels, goats and donkeys are a measurement of wealth and prestige here. Each tribe has its own branding symbol, and families personalize those marks for further identification. A camel, the Cadillac of animals, runs $1,000. A cow, providing milk or meat, can cost $400. And a donkey, reliable but less impressive, can set a family back about $150.

At refugee camps, where thousands of Africans have fled, threats of reprisals are openly discussed. Without a government willing to compensate them for their lost wealth, village elders said, revenge will become the only way to reclaim it.

Some of the animals have been eaten at celebratory victory meals, international aid workers investigating the issue said. But most have wound up in large markets across Darfur, including a massive slaughterhouse in El Obeid, the capital of the neighboring state of North Kordofan, investigators said. Others have been sent to other countries -- to Chad, the Central African Republic and the Gulf states, where demand and prices for good beef are high.

International aid organizations and a Sudanese group are investigating the thefts and trying to trace the profits to determine whether they have reached high levels of government. But many victims and traders said the money has largely stayed in the hands of the Janjaweed.

"Janjaweed and Janjaweed leaders are getting rich off of this," said Adam Azzim Mohamed, a professor at the University of Khartoum, who is tracking the profits from the sales. "There is an expression in Darfur that says, 'A man is powerless without his herds.' What people outside Sudan may not realize yet is how important the reprisals regarding these animals may be. There will not peace until the government sorts out this. . . . Otherwise it can be very dangerous."

The conflict began 20 months ago when two African groups rebelled against the Arab-dominated government, saying they had been politically marginalized. International organizations say the government armed the Janjaweed to put down the uprising. Facing international pressure, the government conceded that it had armed some of the militiamen, but says most are bandits outside its control.

Government officials said police in Darfur were investigating reports of stolen herds and that victims would be compensated if their claims were proved. But human rights advocates and villagers said they saw no evidence of such an investigation. They countered that the Sudanese government has failed to hold anyone accountable for crimes, creating an atmosphere of impunity.

"The international community has got to hold the government responsible for what has happened. They have trained, equipped and deployed the Janjaweed forces," said Peter Takirambudde, executive director of the Africa division of Human Rights Watch. "If you talk about people ever returning to their normal lives, clearly this would be a key consideration. How can they go back without any of their principal assets? Obviously, these guys don't have Swiss bank accounts. I think the international community must remain focused on pressuring the government to get this done."

When Charles Snyder, the State Department's senior representative on Sudan, visited Khartoum last month, he pressed the government to start a reconciliation process for Darfur.

"There is a major tear in the social fabric of Darfur," Snyder said. "There has to be a system set up to hold individuals responsible."

But so far, there are no signs that international pressure has stopped the livestock thefts. At this meat market in Nyala, Nemen Maki Fage, an Arab trader and butcher, attributed the abundance of animals to "spoils of war." He said he was unconcerned about tribal markings on the cattle.

Besides, he said, it was possible that the animals had not been stolen but had simply been sold.

"The police don't come here to investigate. And the prices of the cattle are cheap, and no one stops us," he said, proudly showing five head of cattle he bought for $30 each. "This is Darfur right now."

Days later, Rhani, the local tribal leader, read from stacks of police reports: April 16 in Nyala -- 12 people killed, 410 sheep taken. Two months ago, in a nearby village, 400 horses stolen, and on and on. In total, he said, he has reported 300 cases of stolen animals.

"But the government is quiet," he said. "I report them and keep the papers. If there is ever justice, I will use them."

Later that afternoon, Rhani again drove to the market. In one corner, Arab traders carrying cell phones prodded the cattle. Calls were made. Money changed hands quickly.

In another corner, the pungent smell of freshly slaughtered meat rose in waves as it was cooked over charcoal at dozens of tiny stands.

"They are roasting our wealth," Rhani whispered.

The stench of detritus -- a jumble of wrappings, stripped-clean bones and plastic soda bottles -- filled the dirt footpaths. Women carrying tomatoes, basil, onions and plastic bags of salt hawked their goods.

A hulking leg of goat rested on a donkey cart, flies swarming happily atop its pink skin. The meat was carried to the grill, where a long line of customers waited.

Stolen camels and other animals have flooded this market in Nyala, in Sudan's Darfur region, since Arab militiamen began terrorizing African farmers.