The Ebola outbreak in the Democratic Republic of Congo has spread to a city, the World Health Organisation said on Thursday, raising concern the deadly virus may prove tougher to contain.
"One new case of Ebola virus disease has been confirmed in Wangata, one of the three health zones of Mbandaka, a city of nearly 1.2 million people in Equateur Province in northwestern Democratic Republic of the Congo," the UN's health agency said in a statement. 
The outbreak, publicly declared on May 8, had previously been reported in a rural area of Equateur that lies roughly 150 kilometres from Mbandaka.
"This is a concerning development," WHO director-general Tedros Adhanom Ghebreyesus said in the statement. 
The agency said it was deploying around 30 experts to Mbandaka "to conduct surveillance in the city."
Forty-four cases have been reported in the outbreak so far, including three confirmed, 20 probable and 21 suspected, according to the WHO's tally. 
dpa adds: "The arrival of Ebola in an urban area is very concerning and WHO and partners are working together to rapidly scale up the search for all contacts of the confirmed case in the Mbandaka area," said Matshidiso Moeti, WHO Regional Director for Africa.
"We are now entering a new phase of the epidemic which is now affecting three health zones, including an urban health zone," Health Minister Oly Ilunga Kalenga said in a statement.
On Wednesday more than 5,000 Ebola vaccines arrived in Congo as part of the UN's efforts to stem the outbreak in the central African country.
The vaccine is the same experimental substance that has been proved to be safe and effective in a trial among 7,500 people in Guinea in 2015.
Guinea, along with Liberia and Sierra Leone, were at the centre of the 2014 Ebola outbreak in West Africa that killed 11,000 people.
In the current outbreak, the WHO has said it is worried that the highly infectious and deadly haemorrhagic fever could spread from Congo to neighbouring Congo-Brazzaville and the Central African Republic.
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