The first case of Ebola has been confirmed in a major Congolese city. Mbandaka has a population of one million people. Previously the outbreak was centered on the small town of Bikoro. Mbandaka is around 130 kilometres from Bikoro. The World Health Organisation says the case in the city could see an explosive increase of Ebola in the region. Meanwhile, more than 4-thousand experimental vaccines have arrived in the DRC, and will be administered in the affected areas. CGTN's Robert Nagila is in the DRC, and filed this report.

As of late Wednesday, there'd been 23 deaths believed linked to this outbreak. And more than 40 suspected, probable or confirmed cases. But they've been in a relatively isolated area in the DRC's north-west. News of a case in the city of Mbandaka changes the dynamic. Mbandaka has a population of a million people. And it sits on the banks of the Congo River, a major route for trade and transport into the capital, Kinshasa. The Congo Republic is on the other side of the river.

Health Minister Oly Ilunga Kalenga says authorities will step up attempts to trace possible contacts in and out of Mbandaka. Even before this announcement, officials were trying to track down around 4000 people all over the country's north-west, who may have had contact with the confirmed Ebola cases.

The World Health Organisation has flown in an experimental vaccine. The Health Ministry says vaccinations will start early next week. More than 300 body bags also have been flown in.

Robert Nagila, CGTN, Tanganyika, DRC.