He says they've made sure social distancing is in place at church events.
NPHET is to advise the government whether cities could be placed on higher COVID restrictions instead of locking down entire counties.
It comes amid concerns about Cork, Waterford, Limerick and Galway as cases there continue to rise.
Donegal will enter level three restrictions from midnight and the Taoiseach has said health officials will be working with their counterparts in the north to ensure a synchronised response both sides of the border.
Micheál Martin also says NPHET will be examining whether cities could be treated differently to the rest of the county they're in:
A midlands priest says people need to think carefully about how they celebrate church events.
The surge in covid cases in Donegal has been traced back to social gatherings, including communions and confirmations.
But Father Paddy Byrne, who oversees six parishes in Laois, says he ensures all church ceremonies abide by health guidelines, and says outbreaks are coming from family celebrations afterwards: