Democratic Republic of Congo declared a new outbreak of the deadly Ebola virus on Thursday, three years after its last one, saying there were now 28 suspected cases and 15 deaths.

The health ministry said samples tested on Wednesday had confirmed the presence of the Zaire strain of the virus.

It said the initial signal for the outbreak came when a 34-year-old pregnant woman was hospitalised in Kasai province on August 20 with symptoms including high fever and vomiting. It did not say whether the woman had died.

The World Health Organization said case numbers were likely to increase as transmission was ongoing.

Ebola is a rare but often fatal illness in humans. It is transmitted through contact with blood and other bodily fluids.

Congo has recorded over a dozen outbreaks, the last one in 2022 in the Equateur province.

A devastating 2018-2020 outbreak killed nearly 2 300 people.

The WHO said Congo had a stockpile of treatments as well as 2 000 doses of the Ervebo vaccine that will be transported to Kasai to vaccinate contacts and frontline health workers.

It will deliver two tons of supplies including mobile laboratory equipment and medical supplies.