The Acting Chief Medical Officer Dr Ronan Glynn has advised people living in Dublin to "keep their social contacts as low as possible".
It comes after 231 new cases of COVID-19 were confirmed in the Republic today, bringing the total amount to 29,534.
No new deaths were recorded in the past 24 hours, meaning the number of coronavirus-related deaths here stands at 1,777.
Of the new cases, 133 are located in the Dublin region.
Kildare follows with 18 news cases, with 13 recorded in Limerick.
In a statement with the release of today's figures, Dr Glynn said that while there are "a significant number of cases in Dublin today", it was important to look at the figures "in the context of our 7 and 14-day incidence rates".
He said that NPHET "pays close attention to trends and patterns in the data over time in order to analyse the progression of COVID-19 both across the country and in particular areas or settings".
He added: “However, it is now really important that people in Dublin keep their social contacts as low as possible.
"It is also vitally important that if you feel unwell, you self-isolate immediately.
"Phone your GP without delay if you have a concern. Know the symptoms to pay close attention to - cough, shortness of breath, fever, loss of sense of taste or smell."
His comments come as two new testing centres opened in Dublin today which will be able to swab a combined daily total of 200 people.
The clinics are located in Castleknock in west Dublin and at the Handball Centre at Croke Park in the north inner city.
Dr Glynn has asked people to come forward for testing if they have any concerns.
