New COVID-19 restrictions imposed on Laois, Kildare, and Offaly could be extended to other counties if the number of daily infections continues to rise, according to the National Public Health Emergency Team (NPHET).
Travel restrictions have already been imposed on the three counties for the next fortnight, while many businesses have been ordered to close due to the high number of infections and clusters.
Acting Chief Medical Officer Ronan Glynn said that there was no guarantee that restrictions would be lifted in two weeks' time and warned the Government that the restrictions could be imposed on any other county in the future.
The measures are a step back towards the total lockdown imposed on Ireland during the peak of the COVID-19 pandemic.
Residents of Kildare, Offaly, and Laois can only travel within their own county except for work, medical appointments, or vital family reasons.
Restaurants and cafes in the three counties will have to close their indoor areas from today, while hotels will also have to close as soon as current guests return home.
Indoor gatherings will now be restricted to no more than six people coming from no more than three different households, while outdoor gatherings will be restricted to 15 people.
All cinemas, theaters, gyms, betting shops, and leisure centers will have to close in the three counties from today.
There have been 289 cases of COVID-19 diagnosed in the three counties in the past two weeks, almost half of Ireland's total cases in that timeframe.
Almost all cases are linked to outbreaks in food-processing plants in the region, with two factories reporting more than 80 cases.
If other Irish counties exhibit similar growth in new cases, then they may find themselves under similar lockdown measures in the near future, according to NPHET.