Arrests were made as protesters brought mock gallows to the Irish parliament, hindering access to the building.
The speaker of the lower house of the Irish Parliament has described protests which included a mock gallows as an "attack on democracy".
Sean Ó Fearghaíl told RTÉ that tolerating such behaviour could "bring us to where America arrived at Capitol Hill in the aftermath of the last [US Presidential] election."
Protesters took mock gallows and photographs of high-profile politicians to a demonstration outside the Oireachtas as it returned following the summer recess.
Some demonstrators carried placards depicting politicians, including Ireland's Taoiseach, or Prime Minister, Leo Varadkar, as 'traitors'. Thirteen arrests were made "in connection with incidents around government buildings", according to Irish police.
Those protesting raised COVID conspiracy theories, anti-immigration messages and attacks on transgender rights.
A video on social media showed an Independent member of the parliament, Michael Healy-Rae, being escorted by police officers as protesters shouted abuse and insults at him.
It all comes after protests elsewhere in Ireland, including some at libraries, where some have complained against what they consider inappropriate reading material for children. In some cases libraries have been forced to close and there have been clashes with counter-demonstrators.
Deputy prime minister Micheál Martin described the behaviour as "fascist-like".
The country's justice minister, Helen McEntee, has sought a security review over the "appalling scenes of violence and intimidation".
Ó Fearghaíl said that it's important that parliament is open and accessible to people and protest is an acceptable part of the democratic process, but that the protesters "were not there to serve any particular cause because they are incapable of that".
"We can no longer tolerate something that is about undermining attacking and undermining democracy and spreading hate - whether about migrants or whatever its about," he added.
The People Before Profit party warned that "for too long it has been assumed that Ireland would remain immune to far-right developments in the rest of the world."
"After yesterday's mini re-enactment of a Trump-style protest, we can no longer assume that."