Following an emergency conference, the head of an expert panel of WHO advisers, Robert Steffen, said there is "strong reason to believe that this situation can be brought under control."

Steffen lauded the quick response by the Congo government, the WHO and aid groups, but also warned the recent spread of the outbreak to the city of Mbandaka had increased the risk that the virus would be transmitted within the country and to neighbouring Congo-Brazzaville.

Steffen and the other WHO experts called on neighbouring countries to prepare for possible infections and to strengthen their ability to detect such cases.

The experts said screening of departing travellers on Congo airports and on the Congo river was important, but they said there should not be any international travel bans into the country.

"In total since the start of the epidemic, there have been 45 cases of hemorrhagic fever, including 10 suspected cases, 21 probable cases, and 14 confirmed cases," the ministry said late Thursday.

One of the most contagious viral diseases known, Ebola's symptoms are extraordinarily painful and include severe vomiting, diarrhea, fever, impaired kidney and liver function as well as internal and external bleeding.

The United Nations and aid organisations are racing to prevent the recurrence of an outbreak similar to the one in 2014, when 11,000 people died in a West African epidemic that was centered in Guinea, Liberia and Sierra Leone.

The executive of the European Union announced the release of €1.6 million ($2.5 million) to help tackle the current outbreak, with most of the money going to the WHO to provide logistical support.