The Ebola outbreak in the Democratic Republic of Congo has spread to two more northeastern provinces, Haut-Uele and Tshopo, the country's public health institute said in its latest report.

The number of confirmed Ebola cases across the country rose to 1 926, including 702 deaths, official data showed late on Sunday. Four cases were recorded in Tshopo, including two deaths, with one death confirmed in Haut-Uele, as of Saturday.

The latest Ebola outbreak, Congo's 17th, was declared on May 15 and has been largely concentrated in Ituri province, with cases also reported in North Kivu and South Kivu provinces.

The often fatal viral disease spreads through direct contact with bodily fluids from infected people or animals and causes symptoms that can include high fever, vomiting and internal ⁠and external bleeding.

Reuters reported in late June that Congolese health authorities had started tracing people potentially exposed to Ebola in Tshopo and Haut-Uele, but until now the two provinces had not been included in the government's daily reports.

"Although current investigations suggest that all cases detected in these two provinces are primarily imported from Niania in Ituri, it is necessary and appropriate ... to consider these two provinces as an epidemic zone," the National Institute of Public Health said in its report dated July 11.

Tshopo's provincial capital is Kisangani, one of Congo's largest cities. Haut-Uele shares borders with South Sudan and the Central African Republic.

A senior World Health Organization official told Reuters last week that the true scale of the outbreak could be two to four times larger than official data indicate because four out of five new Ebola cases have no known link to existing patients.