The Department of Agriculture in Northern Ireland has temporarily suspended some food checks and Larne and Belfast ports following safety concerns for staff there.
A local council withdrew staff from the ports carrying out post-Brexit checks amid an "upsurge in sinister and menacing behaviour" over the Northern Ireland protocol.
According to The Irish Times, the North's Minister for Agriculture Edwin Poots posted on social media on Monday evening that he took the decision to withdraw staff from both ports, saying their safety "remains paramount".
Councillors from Mid and East Antrim Council voted unanimously to withdraw all council staff from Larne port with immediate effect on Monday evening following safety concerns.
"Graffiti within the local area referencing increasing tensions around the Northern Ireland protocol and describing port staff 'targets'" were among the concerns highlighted by the council.
The council apologised for any disruption caused by the withdrawal of the 12 employees, in addition to a number of senior council officers, adding a risk assessment would be carried out with the Police Service of Northern Ireland (PSNI), the Foods Standards Agency and the Department of Agriculture.
'Troubling graffiti'
The council's mayor, DUP councillor Peter Johnston said there had been an increase in "deeply troubling graffiti and a very notable upping of community tensions towards the Nothern Ireland protocol in recent days".
Mr Johnston added the staff would continue to be withdrawn from the port until they had "very reall assurances and full confidence that they can go about their duties without fear, threat or concern for their wellbeing".
SDLP councillor Eugene Reid said it was a "disgrace" that such action had to be taken to protect staff. "The threats need to be lifted and those responsible need to get off the backs of these workers," he said.
Last week, the PSNI assistance chief constable Mark McEwan warned the House of Commons Northern Ireland Affairs Committee of increased discontent among loyalist communities since the Northern Ireland protocol came into effect at the start of the year.
Unionist parties in the North have repeatedly called for the protocol to be scrapped, particularly following the European Union's move to trigger Article 16 in an attempt to avoid vaccines manufactured in the EU being exported to the UK through the North.
European Commission president, Ursula von der Leyen has since expressed her regret over the EU's decision last week, which the EU was quickly forced to do a U-turn over after criticism from Ireland and the UK.
Speaking to RTÉ's Morning Ireland today, Minister for Health Stephen Donnelly condemned the intimidation of port staff, describing such behaviour as "completely unacceptable".
Mr Donnelly said the issue had been discussed at a meeting with Northern Ireland ministers last night, adding the protocol existed because of Brexit, and it was important that Northern Ireland retain its access to the EU.
Taoiseach Micheál Martin also criticised the "sinister" behaviour saying it was a very worrying development.
"I would condemn the intimidatory tactics against workers who should of course be allowed and facilitated in going about their daily work.
"It's a very sinister and ugly development and obviously we will be doing everything we possibly can to assist and to defuse the situation."
