The World Health Organization has declared an Ebola outbreak in the Democratic Republic of Congo and Uganda a "public health emergency of international concern".
The WHO said the outbreak, caused by the Bundibugyo virus, does not meet the criteria of a pandemic emergency but said countries sharing land borders with DRC are at high risk for further spread.
The UN health agency said in a statement that 80 suspected deaths, eight laboratory-confirmed cases and 246 suspected cases had been reported.
The DRC health ministry had said on Friday that 80 people had died in the new outbreak in the eastern province.
There could potentially be a much larger outbreak than what is currently being detected and reported, the WHO said, given the high positivity rate of the initial samples and increasing number of suspected cases being reported.
The outbreak is "extraordinary" as there are no approved Bundibugyo virus-specific therapeutics or vaccines, unlike for Ebola-zaire strains, it said.
The DRC-Uganda outbreak poses a public health risk to other countries, with some such cases of an international spread already documented, the agency said.
The WHO advised countries to activate their national disaster and emergency-management mechanisms and undertake cross-border screening and screening at main internal roads.
In Uganda's capital, Kampala, two apparently unrelated laboratory-confirmed cases, including one death, were reported, from people travelling from the DRC, the WHO said.
A laboratory-confirmed case was also reported in the DRC capital, Kinshasa, from a person returning from Ituri, the WHO said.
Bundibugyo virus-disease contacts or cases should not travel internationally, unless as part of a medical evacuation, the WHO said.
The agency advised immediately isolating confirmed cases and monitoring contacts daily, with restricted national travel and no international travel until 21 days after exposure.
At the same time, the WHO urged countries not to close their borders or restrict travel and trade out of fear, as this could lead to people and goods making informal border crossings that are not monitored.
