An ebola outbreak suspected of killing 80 people has been declared a “public health emergency of international concern” amid risk of further spread.

The disease has broken out in the Democratic Republic of Congo and Uganda and there are fears it could cross borders.

The World Health Organisation issued the warning and said the outbreak could be larger than what had been detected and reported.

The outbreak is considered “extraordinary” as there are no ‌approved vaccines or therapeutics for this strain of ebola, which is caused by the Bundibugyo ​virus.

Symptoms may start with fever, muscle pain, fatigue, headache and sore throat, and progress to vomiting, diarrhoea, a rash and bleeding.

The WHO said the outbreak did not meet the criteria of a pandemic emergency but countries sharing land borders with DRC were at high risk.

The UN health agency said 80 suspected deaths, eight laboratory-confirmed cases and 246 suspected cases had been reported ‌as of Saturday ‌in DRC’s ⁠Ituri province.

The DRC health ministry had said on Friday (local time) that 80 people had died in the new outbreak in the eastern province.

There could potentially be a much larger outbreak than what was currently being detected and reported, the WHO said, given the high positivity rate of the initial samples and increasing number of suspected ⁠cases emerging.

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. It advised countries to activate their national ​disaster and emergency-management mechanisms and begin cross-border screening and screening.

In Uganda’s capital, Kampala, two apparently unrelated laboratory-confirmed cases, including one death, were reported on Friday and Saturday, 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.

-with AAP