The wearing of face masks on all forms of public transport in Ireland is now compulsory.
Regulations to enforce this come into effect from today, July 13.
Anyone who refuses to wear a face covering on public transport could be met with a fine of up to €2,500, as well as a possible prison sentence of six months.
A driver or other relevant person has the right to deny entry to anyone not wearing a face covering, or refusing to do so. Gardaí can also be notified.
There have now been 25,628 confirmed cases of Covid-19 in Ireland, according to latest government figures.