The International Federation of Red Cross and Red Crescent Societies says the response to the new Ebola virus outbreak in Democratic Republic of Congo's North Kivu province will be "highly complex" given the armed unrest in the region.
Dr Fatoumata Nafo-Traore, regional director for Africa, says the proximity to a city of more than 230 000 people and an international border also complicates the response.
DRCC's health ministry on Wednesday announced four Ebola cases in Mangina village, about 30km from Beni city. It says 20 people have died from a hemorrhagic fever.
The outbreak comes just over a week after DRC declared the end of an outbreak in the northwest that killed 33 people. The World Health Organisation says the outbreaks are likely not linked.
International health experts have arrived in the region.
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