An incident at a site in Co Tipperary, which was earmarked for modular homes for refugees, has been described as "shocking and intolerable".
Gardaí said the incident occurred at Heywood Road, on the edge of the town, and that security personnel contracted to work on the site were assaulted by a number of individuals.
One of the workers was hospitalised while a number of vehicles were damaged.
Minister of State Ossian Smyth said the attack was "horrific" for the worker and their family.
Speaking on RTÉ's Saturday with Colm Ó Mongáin, the Green Party TD said the incident was "shocking and intolerable," and while people have a right to protest and debate, "there is no right to attack people that you disagree with or to intimidate other people who are loosely related".
He said such behaviour cannot be normalised.
Minister Smyth said people are being emboldened by social media, and what in the past would have been shameful and unacceptable, is now "becoming more normal not just in Ireland but across Europe".
Labour leader Ivana Bacik said what happened in Clonmel is not reflective of the enormous welcome being shown by communities across the country to people seeking refuge.
Speaking on the same programme, she said the "small minority" who spread hatred needed to be pursued with great rigour by every available means.
Ms Bacik also said that allowing people to be housed in tents without offering alternative secure accommodation from the State is a failure of Government policy.
She said she is concerned that the use of tents instead of a proper accommodation policy amounts to a kind of "Rwanda policy".
An increasing number of tents sheltering unaccommodated asylum seekers have been pitched along a section of the Grand Canal in Dublin.
Recent figures show there are around 1,780 International Protection applicants awaiting an offer of State-provided shelter.
Meanwhile, Independent TD Seán Canney said the use of violence for political expedience is something that should never be tolerated.
"Regardless of the issue, there are ways of actually explaining your view on something, lobbying for it, protesting about it, but to actually to harm another person is actually going way beyond what democracy should afford in any country," he said.
