There were no new deaths from the virulent haemorrhagic fever, which usually causes victims to die of bleeding through various orifices, Health Ministry Spokesman Paul Kabwa said.

Twenty two people have so far died of the fever.

"Cumulatively, we have got 101 cases of Ebola -- those who fit the case definition," Kabwa said, adding that all were in western Uganda's Bundibugyo district, except for two in Kampala, including a doctor who died.

He said 39 had been admitted to hospital in serious condition and 350 others suspected of having been exposed to the virus were being urged to stay at home.

"They are being observed because they are possible contacts with Ebola cases," Kabwa said. "They are not being confined."

The outbreak, which started in August, has sparked panic amongst officials, health workers and the public.

"A bigger Ebola bomb could explode, claiming many more lives," Bundibugyo district chairman Jackson Bambalira was quoted as saying in the state-owned New Vision daily on Friday.

Bundibugyo borders Democratic Republic of the Congo, whose Ebola river gave the virus its name after some of the first cases of Ebola were recorded in its valley in 1976.

The independent Daily Monitor reported on Friday that Congo had sealed the border with the district. Congolese officials were not immediately available for comment.

Neighbours Kenya and Rwanda, to the east and southwest, respectively, are screening travellers entering from Uganda.

The four-month delay between the start of the outbreak and confirmation last week that it was Ebola has raised suspicions the government covered it up so as not to scare delegates -- Britain's Queen Elizabeth and 53 heads of government -- who met in Kampala two weeks ago for a Commonwealth summit.

The government denies it withheld information. It says it took time for test results to come back from the Centres for Disease Control and Prevention in the United States.

Commentators have criticised the government's response as sluggish and say Uganda should have learned from an Ebola outbreak in 2000, when 425 people caught it and over half died.

"When Ebola first struck in 2000 in northern Uganda, we were plunged into panic. Seven years later when we should have been better prepared ... we are ill-equipped as before," read an editorial in the Monitor on Friday.

Uganda's medical workers union have called on staff to refuse to care for patients unless they have proper protective gear, following the death of four medical staff.

The government says all those treating Ebola cases are protected. "We are distributing protective gear. We don't want to risk our own staff," Kabwa said.