A third confirmed case of the Ebola virus in the Democratic Republic of Congo (DRC) has led the World Health Organisation to escalate its assessment of the national public health risk to "very high".
The latest confirmed case was in Mbandaka, the provincial capital of 1.2 million people, the DRC's Ministry of Health said.
It was the first case in the latest outbreak to be confirmed in an urban environment, sparking fears it would lead to a wider contamination.
"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 Dr Matshidiso Moeti, WHO regional director for Africa.
Two previous cases were confirmed elsewhere in Equateur province earlier this month, where the contagion is believed to have already killed 23 people.
The discovery of Ebola in this bustling port city on the River Congo also led WHO to raise its assessment of the regional risk to "high".
Experts said it was therefore incumbent on authorities to heed the lessons learnt in the 2014 West African outbreak to prevent the virus spreading further.
"There is absolutely no reason why this current outbreak should grow any further," said Dr Kamalini Lokuge, the head of the Australian National University's Humanitarian Research Program.
"In order for us to make sure that it's controlled effectively, we have to implement what we know works.
"We know that in West Africa we didn't do that well enough, thoroughly enough, early enough," Dr Kamalini said.
The West African epidemic became the worst outbreak of the virus, killing more than 11,000 people.
This time, the race to encircle the contagion is underway: WHO has deployed about 30 experts to conduct surveillance in Mbandaka, and Medecins Sans Frontieres opened treatment centres in the city's hospital and the small town of Bikoro, where the latest outbreak began.
"This is a concerning development, but we now have better tools than ever before to combat Ebola," WHO director-general Tedros Adhanom Ghebreyesus said.
