Local health officials in Democratic Republic of Congo reported 21 patients showing signs of haemorrhagic fever and 17 deaths in the affected area before an Ebola outbreak was confirmed.
Medical teams dispatched to the zone took five samples from suspected active cases and two tested positive for the Zaire strain of the Ebola virus, the country's health ministry said in a statement.
It is the ninth time Ebola has been recorded in the DRC, whose eastern Ebola river gave the deadly virus its name when it was discovered there in the 1970s.
The latest incidence of the disease comes less than a year after the central African country's last outbreak, in which eight people were infected of whom four died.
Ebola is believed to be spread over long distances by bats, which can host the virus without dying, as it infects other animals it shares trees with such as monkeys. It often spreads to humans via infected bushmeat.
Congo's vast, remote geography gives it an advantage, as outbreaks are often localised and relatively easy to isolate.
In West Africa, an Ebola outbreak that ended two years ago killed more than 11,300 people and infected some 28,600 as it rolled through Guinea, Sierra Leone and Liberia before finally being contained.