At least 70,000 people have died since March as a result of poor conditions in refugee camps in Sudan's Darfur, the United Nations health agency said Friday.

The World Health Organization warned that the death toll will climb unless other countries provide more aid.

"We are running on a threadbare, hand-to-mouth existence, and if the plight of these people in Darfur is as important to the international community as it seems to be, then we would have expected more long-term support," said Dr. David Nabarro, head of crisis operations for the UN organization.

Kaltum Ibraheem, 35, from an Arab-African tribe holds her daughter Zynab Hussein, 2, in the hut they now live in at Mistiria in North Darfur, Sudan. (AP Photo)

• INDEPTH: Sudan

Nabarro said the major cause of death in the camps appeared to be diarrhea, as well as fever and respiratory disease.

The revised death toll cited by the UN does not include those killed in ongoing violence being carried out by Arab militias against Darfur's black residents and from rebellion by tribal groups.

In September, Nabarro estimated that about 50,000 people had died since the conflict began 19 months ago. About 7,500 of those deaths were due to violence, he said.

The conflict has forced 1.4 million villagers from their homes in the past year and a half.

• FROM OCT. 6, 2004: Sudan official to U.S.: Send troops to Darfur

"We still don't have a significant enough popular perception around the world of the enormity of the suffering" from the Darfur crisis, Nabarro said. "Disease and suffering is being experienced on a quite extraordinary and inhuman scale."