The death toll from an outbreak of the Ebola virus in the Djera region of northern Democratic Republic of Congo has risen to 31, the government said, as the World Health Organisation confirmed there was no link with an epidemic in West Africa.
Previously, the government said there were 13 dead.
The separate outbreak in West Africa has killed more than 1,550 people since it was first reported in the forests of southeastern Guinea in March.
The WHO said on Tuesday (local time) that the outbreak in Congo was a "distinct and independent event, with no relationship to the outbreak in West Africa". It added that there were a total of 53 cases and said health care workers were tracing 160 contacts.
The Zaire strain of the deadly virus is indigenous to Congo and there have seven outbreaks in the country since it was first discovered there in the remote Equateur province in 1976.
The first victim of the current Congo outbreak was a pregnant woman who butchered a jungle animal in the village of Ikanamongo and died on 11 August.