Six people have died from an outbreak of Marburg virus in Rwanda, the health minister has announced.
Sabin Nsanzimana said most of the victims were healthcare workers in a hospital intensive care unit.
Twenty cases have been identified since the outbreak was confirmed on Friday.
Marburg, with a fatality rate of up to 88%, is from the same virus family as Ebola. It spreads to humans from fruit bats and then through contact with bodily fluids of infected individuals.
Symptoms include fever, muscle pains, diarrhoea, vomiting and, in some cases, death through extreme blood loss.
There are no specific treatments or a vaccine for the virus but a range of blood products, drug and immune therapies are being developed, according to the World Health Organization.
Rwanda says it is intensifying contact tracing, surveillance and testing to help contain the spread.
The health minister said officials were tracking about 300 people who had come into contact with individuals affected by the Marburg virus.
He urged people to avoid physical contact, to help curb the spread.
Authorities have previously advised the public to stay vigilant, wash their hands with clean water and soap or sanitiser and report all suspected cases.
Most of the reported cases have been in the capital, Kigali.
The US embassy in the city has advised its employees to work remotely for the next week.
This is the first time Marburg has been confirmed in Rwanda.
Neighbouring Tanzania reported an outbreak in 2023, while three people died in Uganda in 2017.
