There has been a record high number of 934 coronavirus cases recorded in Northern Ireland on Friday.
That is over 500 more than the previous record, after 424 people tested positive on Wednesday.
Some 2,623 people have tested positive for the virus in the North in the past week - which is 20% of all its cases.
One further death has also been reported.
People have been urged to avoid all unnecessary travel across the Irish border.
In a joint statement last week, Acting Chief Medical Officer Dr Ronan Glynn and his Northern Ireland counterpart Dr Michael McBride appealed to people on both sides of the border.
They said: "Given the current number of new cases in Donegal and neighbouring areas of Northern Ireland in Derry, Strabane and Fermanagh we would appeal to everyone to avoid all but necessary travel across the border.
"It is also recommended that employers on both sides of the border make every effort to facilitate employees to work from home in so far as is possible.
"We realise that for those living in border areas this will not be welcome news but we must prevent further spread of this virus and we can only do so by working together to protect each other."
It comes as the coronavirus reproduction - or 'R'- number for the UK is now as high as 1.6.
The R number is now between 1.3 and 1.6 - up from between 1.2 and 1.5 last week, according to the UK government's advisory committee SAGE.
In England, the R number is highest in London and the north east and Yorkshire - it is lowest in the east of England.
If the reproduction rate is above one, it means the number of cases will increase exponentially.
But if the R number is below one, the disease will eventually peter out as not enough new people are being infected to sustain the outbreak.
The new UK figure represents transmission over the last few weeks rather than a current snapshot, due to the delay between someone being infected, having symptoms and needing healthcare.
