One of the dead was a 15-year-old girl and a total of nine cases have been reported.
"Four additional people who contracted the virus -- all contacts of the deceased and including the child of one of the fatal cases -- are being treated in an isolation unit at the Wangata Hospital in Mbandaka," UNICEF said in a statement.
"The deaths occurred between the 18th and 30th of May but they were only confirmed as Ebola-related yesterday."
It's the DRC's 11th outbreak of Ebola. The country is still coping with an outbreak that began in 2018 and killed more than 2,200, CNN said.
"The announcement comes as a long, difficult and complex Ebola outbreak in eastern Democratic Republic of the Congo is in its final phase, while the country also battles COVID-19 and the world's largest measles outbreak," the World Health Organization said in a statement.