Three cases of the South Africa coronavirus variant have been detected in Northern Ireland, the Department of Health has confirmed.
The department said transmission risk was low and that officials were trying to trace contacts linked to the cases.
It is the first time the variant has been found in Northern Ireland.
Health Minister Robin Swann said it underlined the need for caution but did not mean the variant would become the most dominant in Northern Ireland.
The variant was detected in the Republic of Ireland last month.
"Identification of a confirmed case or cases of this variant in Northern Ireland was inevitable at some point," said Mr Swann.
"The best way to stop variants developing or spreading is to keep pushing down infection rates and transmission of the virus in our community.
"All variants... spread in the same way and we all have an important role to play in stopping the spread of this virus."
Sinn Féin MLA Colm Gildernew, the chair of the Stormont Health Committee, said the confirmation of the South Africa variant in Northern Ireland was "deeply worrying".
Where did the variant come from?
The Public Health Agency (PHA) in Northern Ireland said it could not comment on how the South African variant entered Northern Ireland as there was "a need to protect the confidentiality of those cases".
"In terms of community spread, we don't see any evidence of that so we're quite assured that it's unlikely that there will be further spread across Northern Ireland," Dr Stephen Bergin, interim director of the PHA told the BBC's Evening Extra programme.
"If there was an emerging hot spot, we would at that point need to convey that to the public in order to protect public health but we're a very long way from that at this present time. If that happens, it'll be a different conversation.
"Cases primarily come in through travel but I'm not going to comment on the travel history of any individual at this time.
"But we do work with air freight, ports and others to ensure that anyone coming in from red list countries, such as South Africa, completes a passenger locator form and instructions about quarantining are in place."
Dr Bergin said health officials will "continue to be vigilant" and he urged the public of continue following the health advice to limit the spread of Covid-19.
The prevalent strain in Northern Ireland is the Kent variant - B117 - which is thought to be responsible for about 70% of cases.
The South Africa variant shares some characteristics with the Kent variant and is also more transmissible than the original virus.
Preliminary work relating to the the South Africa variant suggests Oxford-AstraZeneca's Covid-19 vaccine should protect against severe disease but offers "limited" protection against mild disease. However vaccines can be redesigned and tweaked to provide a better match in a matter or weeks or months, if necessary.
Dr Bergin said "there is still good evidence and we have good confidence in terms of the [Oxford-AstraZeneca] vaccine protecting against more serious cases of coronavirus".
He urged anyone invited to get their jab to do so as soon as possible.
On Tuesday another five Covid-19-linked deaths were recorded and 225 more people tested positive for the virus in the past day.
Mr Swann told the Stormont assembly that 468,100 people in Northern Ireland had received their first dose of a Covid-19 vaccine.
In total, 499,206 doses have been administered.
Mr Swann said Northern Ireland was seeing the "early shoots" of the benefits of the vaccine programme.
But he warned against "rushing out" of the lockdown restrictions.
"We have often talked of it being the light during these very darks days of the pandemic," he said.
"While we are seeing the uptakes, we are just about the start into the second doses of people receiving the vaccine.
"So I would caution that we don't take those rays of hope and extinguish them too quickly by trying to rush out of the restrictions and the regulations that we are currently in until we see the greater vaccination of the entirety of the population because it will be a balance."