Sudanese officials have reported the country's first cases of the deadly strain of bird flu in poultry.
Egyptian workers have been disinfecting houses to stop the spread of bird flu
Some 100,000 chickens have been culled after the H5N1 strain was found, an official said.
Ahmed Mustafa Hassan also said the owner of a poultry farm had gone to hospital in the capital, Khartoum, with suspected bird flu.
Neighbouring Egypt has already confirmed cases of H5N1, which has killed four people there.
More than 100 people have died from the H5N1 strain since 2003 - the majority of them in Asia.
"Laboratory tests have shown the presence of the bird flu virus in Khartoum and [central] Gezira states," Mr Hassan, a ministry of animal resources official, told reporters.
John Jabbour, the World Health Organization's regional health regulation officer, confirmed there were cases of H5N1 in Sudan but could not confirm any cases of contraction by humans.
So far across the world the disease has mainly affected animals.
But experts fear the virus could mutate into a form that passes easily between humans, possibly sparking a pandemic.
However, there is no evidence that this has happened yet.