The first batch of 4,000 experimental Ebola vaccines to combat an outbreak suspected of killing 23 people arrived in Congo's capital Kinshasa on Wednesday.

The Health Ministry said vaccinations would start at the weekend, the first time the vaccine would come into use since it was developed two years ago.

The vaccine, developed by Merck and sent from Europe by the World Health Organization, is still not licensed but proved effective during limited trials in West Africa in the biggest ever outbreak of Ebola, which killed 11,300 people in Guinea, Liberia and Sierra Leone from 2014-2016.

Health officials hope they can use it to contain the latest outbreak in northwest Democratic Republic of Congo