A second person has died of Ebola on the Democratic Republic of Congo's border with Rwanda, raising fears the deadly illness could spread.
The artisanal miner died on Wednesday morning in the city of Goma, home to two million people, authorities said.
More than 1,600 people have died of Ebola in DR Congo since the outbreak began in August 2018 but those have been in more remote areas.
The World Health Organization called it a global health emergency last week.
It is the highest level of alarm the WHO can sound and has only been used four times previously - including the Ebola epidemic that devastated parts of West Africa from 2014 to 2016, and killed more than 11,000 people.
The latest victim came from the north-eastern province of Ituri but fell ill and was admitted to a health centre in Kiziba, on the outskirts of Goma, on 13 July.
He later developed symptoms of bleeding and bruising, and tested positive to Ebola on Tuesday.
He died on Wednesday morning.
What is the situation in Goma?
Ebola is affecting two provinces of DR Congo - North Kivu and Ituri. Goma is the capital of North Kivu and lies just across the border from the Rwandan city of Gisenyi.
Until now, the virus has been mostly contained to more remote areas, mostly around Beni and Butembo, to the north of Goma.
But the AFP news agency is now reporting that 15 people in South Kivu province have been quarantined amid fears the virus is spreading further.
A priest in Goma died from Ebola earlier this month. The WHO called it a "game-changer", but until now there had not been any further confirmed cases in the city.
Goma is a transport hub so the latest death is of particular concern, as it is far harder to isolate patients and trace contacts in major cities, where highly mobile, large populations are living in close proximity.
There are fears the illness could spread into Rwanda as people travel between Goma and Gisenyi every day.
Although Rwanda has not yet had any confirmed cases, it has set up an Ebola treatment centre and is preparing 23 isolation centres in case of any infections.
"But as long as the outbreak continues in the Democratic Republic of the Congo, there is a very real risk of spread to neighbouring countries."
How bad is the situation in DR Congo?
More than 2,500 people have been infected and two-thirds of them have died.
It took 224 days for the number of cases to reach 1,000, but just a further 71 days to reach 2,000.
About 12 new cases are being reported every day.
Isn't there a vaccine?
It is 99% effective and more than 161,000 people have been given it.
However, not everybody is vaccinated - only those who come into direct contact with an Ebola patient, and people who come into contact with them.
And some of those people refuse to take it.
People give a variety of reasons for not taking it: they don't want to put any external liquid in their body; they have a religion that doesn't want them to take vaccines; they don't believe in Ebola or because they think they don't need it.
The vaccine, made by Merck, was developed during the epidemic in West Africa and has been available throughout the latest outbreak.
It has proven effective but is in relatively short supply so WHO recommended a second vaccine made by Johnson & Johnson to complement it.
But the DR Congo's Health Minister Oly Ilunga complained that the Congolese were being treated as "subjects of experimentation", reports Reuters, and he resigned over the issue.
Why hasn't the outbreak been brought under control?
Tackling the disease has been complicated by conflict in the region.
Since January, there have been 198 attacks against healthcare workers or Ebola treatment facilities leading to seven deaths and 58 injuries.
Another major problem has been distrust of healthcare workers leading to about a third of deaths being in the community rather than at a specialist Ebola treatment centre.
It means those people are not seeking treatment and risk spreading the disease to neighbours and relatives.
There has also been difficulty tracking the spread of the virus.
Is the world doing enough to help?
The WHO has been clear for months that it has insufficient money to tackle the problem.
It had estimated that it needed $98m to tackle the outbreak between February and July. Yet it faced a shortfall of $54m.
What is Ebola?
- Ebola is a virus that initially causes sudden fever, intense weakness, muscle pain and a sore throat
- It progresses to vomiting, diarrhoea and both internal and external bleeding
- People are infected when they have direct contact through broken skin, or the mouth and nose, with the blood, vomit, faeces or bodily fluids of someone with Ebola
- Patients tend to die from dehydration and multiple organ failure