Tests are being undertaken to rule out coronavirus at a hospital in Belfast.
It is understood a patient arrived at the Royal Victoria over the weekend showing symptoms that may or may not be associated with the condition.
The patient is being treated in an isolation unit, but it will be some time before results are returned.
Authorities have suspended planes and trains in and out of the affected Chinese city of Wuhan, where the outbreak is thought to have originated.
The virus has spread to the US, South Korea, Japan, Saudi Arabia, Singapore, Vietnam, Thailand and Taiwan.
The Belfast Health Trust, which runs services in the city, was unable to make any comment.
The Public Health Agency (PHA) also declined to comment.
There is no suggestion at this stage that the patient has coronavirus and the tests are being treated as precautionary.
The Royal is Northern Ireland's largest hospital and a centre for many medical specialisms.
Meanwhile, four people are being tested for suspected coronavirus in Scotland, according to the head of infection medicine at the University of Edinburgh.
Professor Jurgen Haas said he believes there will be many more cases from other cities in the UK.
He said three cases are in Edinburgh and the other is believed to be in Glasgow.
Tests are being carried out and none of the patients have been confirmed as having the disease.
They all travelled to Scotland from Wuhan within the past two weeks and are showing symptoms of respiratory trouble, a red flag for the virus.
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Prof Haas said the Scottish cases emerged overnight, adding: "The situation will be pretty similar in pretty much all UK cities with a large number of Chinese students.
"It's not too surprising. My suspicion is that there will probably be many more cases in many other cities in the UK.
"None of the cases I know of have been confirmed."
He said there is only one laboratory testing for the virus, operated by Public Health England (PHE).
The professor said the cases have been flagged up through the PHE infection guidelines as they travelled to Wuhan within the last 14 days and are showing signs of respiratory symptoms.
The disease has killed 18 people and infected nearly 600.
The Chinese government has effectively locked down Wuhan, cancelling planes and trains there and in the nearby city of Huanggang.
The World Health Organisation has said it is "too early" to declare an international public health emergency over the coronavirus outbreak.
Speaking at a press conference, Dr Tedros Adhanom Ghebreyesus, director-general of the WHO, said: "Make no mistake, this is though an emergency in China.
"But it has not yet become a global health emergency. It may yet become one."
"Make no mistake. This is an emergency in #China, but it has not yet become a global health emergency.— World Health Organization (WHO) (@WHO) January 23, 2020
WHO's risk assessment is that the outbreak is a very high risk in China, and a high risk regionally and globally"-@DrTedros on new #coronavirus
Earlier, the Director of the Health Protection Surveillance Centre in Ireland said there was currently a "moderate to low risk" of the coronavirus emerging in Europe.
Dr John Cuddihy said the risk assessment had been issued by the European Centre for Disease Control and Prevention.
Speaking on RTÉ's Today with Sean O'Rourke, he said risk assessments had been issued to doctors, hospitals and paramedics in Ireland to identify clinical symptoms.
Dr Cuddihy said the coronoavirus presents with flu-like symptoms but a person's travel history is "key" to possible contamination.
He said a recent scare in Dublin with one patient was raised where a person had clinical symptoms and had travelled recently to China.
However, a risk assessment was carried out and the case was de-escalated, which indicated that medics were reacting correctly to any potential concerns.
Public health expert Professor Hugh Pennington from Aberdeen University said coronovirus is the first new virus of 2020 and causes respiratory infections.
He said it can be lethal among the elderly and in those with underlying conditions.
However, he said, the Chinese reaction had been swift and the lockdown in Wuhan was a significant attempt to limit the spread of the virus.
Prof Pennington said a significant scientific test has been developed after just three weeks to diagnose the virus, which mimics other respiratory infections.
Additional Reporting Reuters