The eastern province of North Kivu notified the health ministry of "26 cases of fever with haemorrhagic indications, of which 20 were fatal," Health Minister Oly Ilunga Kalenga said in a statement.
The outbreak has occurred in the Beni region of North Kivu -- the stronghold of a notorious Ugandan-linked Islamist militia called the Allied Democratic Forces (ADF).
"At this point, there is no indication that these two epidemics, which are more than 2,500 kilometres (1,500 miles) apart, are connected," he said.
Six samples taken from hospitalised patients arrived in Kinshasa on Tuesday for analysis by the National Institute of Biomedical Research (INRB), he said.
Of the six, four tested positive for Ebola virus disease.
Twelve health ministry experts will arrive in Beni on Thursday, Ilunga added.
On July 24, Ilunga himself had declared the end to a 10-week outbreak that struck the northwestern Democratic Republic of Congo, claiming 33 lives and prompting international concern.
Cases emerged in the northwestern city of Mbandaka, a city and transport hub on the Congo River with a population of more than a million.
For many experts, that ranked among worst-case scenarios -- contagious disease in an urban setting is far harder to contain than in the countryside, especially in a poor country with a fragile health system.
The epidemic was fought with help from the World Health Organization (WHO), which rushed emergency aid, including protective gear, and unlocked $2 million (1.71 million euros) in fast-track financing.
The WHO provided a vaccine called rVSV-ZEBOV which had proved to be highly effective in trials during the West African pandemic, when it was tested as the outbreak was waning. The unlicensed vaccine was given to frontline workers in the DRC.
The latest outbreak is the 10th in the DRC since 1976, when it was discovered in the north of the country, then called Zaire, and named after a river nearby.
One of the world's most feared diseases, Ebola is a virus-caused haemorrhagic fever that in extreme cases causes fatal bleeding from internal organs, the mouth, eyes or ears.
It has a natural reservoir in a species of tropical African fruit bats, from which it is believed to leap to humans who kill and butcher the animals for food.
Transmission among humans then typically spreads through close contact with the blood, body fluids, secretions or organs of someone who is sick with Ebola or has recently died.
The average fatality rate is around 50 percent, varying from 25 percent to 90 percent, according to the WHO.
In the worst outbreak of Ebola, the disease struck the West African states of Guinea, Liberia and Sierra Leone in 2013-15, killing more than 11,300 people.
Eyewitness? Submit your stories now via social or:
Email: eyewitness@pulse.ng
