An Ebola outbreak has been declared in the Democratic Republic of Congo (DRC) after one person who died of haemorrhagic fever tested positive for the virus. Two others may have also died from the disease.

The case was confirmed following tests on nine people who came down with haemorrhagic fever in Bas-Uele province, in the northeast of the country, in late April, according to a statement from the country's health ministry.

Dr Allarangar Yokouide, WHO’s representative in Congo, said the first teams of specialists should arrive in the affected area of Likati on Saturday. The zone is some 1,300km from the capital, Kinshasa.

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Out of the nine cases, three people have since died, including one who tested positive for Ebola, according to WHO spokesman Christian Lindmeier.

"We need to take this very seriously," Lindmeier told Al Jazeera on Friday.

"It's very important to find all the possible contacts of people who have been infected, who has been in contact, and see whether there is a possible continuation of infection and limit it as much as possible."

Without preventive measures, the virus can spread quickly between people and is fatal in up to 90 percent of cases. There is no specific treatment for the disease.

The last outbreak of Ebola in the DRC in 2014 killed at least 42 people. The country has been hit by Ebola about nine times in all.

"This is not the first outbreak for the DRC so its health system has experience in dealing with it," Lindmeier said.

Ebola killed more than 11,300 people and infected some 28,600 from 2013 as it swept through the West African countries of Guinea, Sierra Leone, and Liberia and caused alarm around the world.

"Our country must confront an outbreak of the Ebola virus that constitutes a public health crisis of international significance," the health ministry said.

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The WHO's Congo spokesman, Eugene Kabambi, said: "It is in a very remote zone, very forested, so we are a little lucky. We always take this very seriously."

The new cluster of Ebola cases will again test one of the world's least equipped health systems. The US Agency for International Development has said an estimated 70 percent of the population has little or no access to healthcare.

In June 2016, WHO declared Liberia free of active Ebola virus transmission. Liberia was the last country still fighting the world's worst outbreak of the disease.

A major trial last year showed a prototype vaccine to be "very effective" against the deadly Ebola virus, according to WHO, which co-funded the study.

The GAVI global vaccine alliance said some 300,000 emergency doses of an Ebola vaccine developed by Merck could be available in case of a large-scale outbreak.

The vaccine, known as rVSV-ZEBOV, was shown to be highly protective against Ebola in clinical trials published last December.