Northern Ireland's chief medical officer has said he expects to see a "rapid increase" in cases of the Covid-19 Omicron variant before Christmas.
Dr Michael McBride was speaking after the first three cases of the Omicron variant detected in Northern Ireland were confirmed yesterday evening.
He said all three confirmed cases are linked to travel and there is not thought to be community transmission of the variant yet.
However, Dr McBridge said there are likely to be more cases than currently identified.
He said measures are being taken to try to delay community transmission of the variant, but that is is "absolutely inevitable".
"I think it is absolutely the case that we have more cases in Northern Ireland at present than we have currently detected given the fact that we have community transmission in other parts of these islands, given the freedom of movement of people in these islands which is really important for so many reasons," he told the BBC's Stephen Nolan Show.
"I think what we will see is a rapid increase in the number of cases identified in the coming days in the run up to the Christmas period.
"What appears to be happening is this virus is getting established very, very quickly in communities where the Delta variant has already been established and it may be the case that in the next period of time that we see this new Omicron variant replacing the Delta variant as the dominant variant in the United Kingdom, in these islands and indeed eventually globally."
Dr McBridge said it is still not known with certainty how likely people are to be infected with Omicron if they have been vaccinated.
He urged that people follow public health advice to attempt to delay the onset of community transmission of the variant for as long as possible.
Two of the confirmed cases of Omicron have been described as within the same household in the greater Belfast area while the third unconnected case was discovered in the South Eastern Trust area.
All the cases are linked with travel from Britain.