The World Food Program says it wants the Sudanese government to allow the resumption of food shipments into Bahr el Ghazal and other regions in the south of the country. Khartoum's refusal to allow food deliveries threatens to cause famine among hundreds of thousands of Sudanese.

The World Food Program says that every month it submits a request to the Sudanese government to deliver food by air to parts of the country, mainly in the south, where there is a chronic lack of food. WFP says the government in Khartoum does not authorize all the distribution locations, but in the past has usually allowed most to go through.

But WFP spokeswoman Christiane Bertiaume says Khartoum has recently refused to grant the United Nations food agency authorization to airdrop supplies. "This time they have refused us authorization for 44 locations in Bahr el Ghazal, in the western and Upper Nile and the Lakes and this is really very [troublesome] because it means that more than 400,000 are at risk," she said.

It is unclear why Khartoum has rejected WFP's request. Last month, a Sudanese government helicopter attacked civilians waiting for food at Bieh village, some 480 kilometers southwest of Khartoum. Seventeen people were killed in the attack and many others were wounded. Khartoum has promised to investigate the attack and to take steps to ensure that such an incident will not happen again.

Ms. Bertiaume says WFP is raising the alarm bell now because Khartoum banned food relief flights four years ago in the Bahr el Ghazal region and that led to many deaths because the people were already suffering from two years of famine. "The situation can deteriorate very quickly in this area because the people are really living on the edge," she said. "So if we cannot go in and help these people, they are in danger."

Ms. Bertiaume says most of the aid recipients have been displaced by years of civil war and have been unable to cultivate their land for food.

The war, one of the longest in Africa, is now in its 19th year. It pits the forces of the mainly Muslim government in the Arab north against Christian and animist groups in the south that are seeking autonomy.