Ebola broke out in early July in Uganda's western Kibale district, some 200 kilometres (120 miles) from Kampala, and around 50 kilometres from the border with Democratic Republic of Congo.
"Two more deaths were last evening recorded at Kagadi Government Hospital in Kibale district... The first death was a female who had earlier tested positive for Ebola," said Dennis Lwamafa, Uganda's director general for health services.
The other death, a "new admission", was feared to have also been due to Ebola, although tests had yet to confirm the exact cause, Lwamafa said in statement.
A health worker from western Uganda last week fell sick and travelled to Kampala, later dying in hospital. It was the first time the killer virus, one of the most virulent diseases in the world, had hit the city of 1.5 million.
A sample has also been collected from a patient in Mbarara, another district of western Uganda, some 100 kilometres from Kibale -- and it is currently being analysed.
In Kibale, health workers are monitoring "two confirmed cases of Ebola and 16 unconfirmed admitted at the hospital isolation facility," Lwamafa said.
In addition, 178 people remain under surveillance in the district, he added.
Ebola, which can cause both internal and external bleeding, spreads by direct contact with the blood or other body fluids of infected persons, according to the World Health Organisation.
The rare haemorrhagic disease, named after a small river in DR Congo, killed 37 people in western Uganda in 2007 and at least 170 in the north of the country in 2000.
Neighbouring nations -- including Kenya, Rwanda, South Sudan and Tanzania -- have also moved to reassure the public, warning people to report to health centres in case of Ebola-like symptoms.
"The people are advised not to panic, as so far we have not received any case within our borders," Tanzanian health ministry official Regina Kikulishe said.
"We advise them to report to a nearby health centre in case they come across anyone with Ebola symptoms."
South Sudan's Minister of Health Michael Milly Hussein said health workers were alerted to "ensure that all suspected cases are detected on time."
Kenya and Rwanda made similar warnings.