People from here who flout face mask regulations while using public transport over the border could be jailed.
Garda confirmed new legislation applies to cross-border travellers after it became compulsory for people to wear masks on public transport in the Republic except in specific circumstances.
From yesterday people who refuse to wear a mask face fines of up to €2,500 and a possible jail sentence of six months.
The wearing of face coverings on buses, trains and ferries, as well as in stations and terminals, became mandatory here last Friday.
Those who are caught flouting the rules currently can only face receiving a fixed penalty of £60, which is reduced to £30 if paid within 14 days.
Exemptions include those who cannot wear face coverings for medical reasons and children aged under 13.
Yesterday at Lanyon Place station in Belfast cross-border rail travellers insisted Northern Ireland should follow the Republic's lead and toughen up the penalties for breaching the regulations.
Alex Collins (22) and Noah Shively-Blinn (21), who were taking the Enterprise train to Dublin, said they had not been aware of the new rules in the Republic, but both gave the measure the thumbs-up.
"In my personal opinion there isn't enough being done to get people to wear masks," Noah told the Belfast Telegraph.
"Coming through the city, I only saw a few people wearing them."
Alex said that while a six-month sentence may seem "a little harsh" he stressed more needs to be done to get people to cover their faces while on public transport.
Co Antrim woman Sian Sutherland (23), who had just returned from a visit to see family, said the majority of people had been following the rules in Dublin.
Sian also said she would welcome the introduction of a similar jail penalty for offenders here.
"Definitely. I just think its about safety. It's not that hard to put a mask on," she insisted.
It is not clear if the threat of jail time over the border has been communicated to passengers from here.
Translink could not be reached for comment yesterday.
The Garda said the mandatory rules regarding face coverings applied to everyone, no matter where they are from, while they are using public transport in the Republic.
However, in a separate statement the Garda said enforcement will always be a "last resort".
"In circumstances where a non-compliant passenger, without reasonable excuse, fails to accept the refusal or comply with a 'relevant person's' request, members of An Garda Siochana may be called to assist," it said.
"Where potential breaches of the public health regulations are identified, and where a person does not come into compliance with the regulations, a file will be submitted to the Director of Public Prosecutions for a direction as to how to proceed."
The PSNI said: "The Enterprise train is jointly run by Iarnrod Eireann (Irish Rail) and Northern Ireland Railway and it is for them to manage their service."