"If the United States is truly sorry for doing too little to stop Rwanda's atrocities, we should act now to stop Sudan's," Tony Hall, a Democrat from Ohio, told reporters here after a four-day visit to southern Sudan and Khartoum. 

Hall said he saw thousands of people forced into mosquito-infested swamps in the famine-stricken Bahr el-Ghazal state by slave traders. 

"The raid was mounted by armed men riding horses and camels, men from a northern ethnic group which is being drawn into the war in this latest twist to the 15-year-old conflict," Hall said. 

"I felt numb as I walked over the bodies and skeletons (of people killed by the raiders)," said Hall, adding that he saw a lot of "severely malnourished" children and adults. 
"I'll never forget one tiny infant who reached out with twig-sized fingers to grab hold of my finger." 

"The United Nations must stand up for the people of southern Sudan. The world needs the UN to tell it like it is, and it hasn't done enough." 

An estimated 1.5 million people in the region have died as a direct result of the war or indirectly from war-related famine and  disease since fighting erupted in 1983.