Over 200 people were involved in Sunday's demonstration.
A number of anti-migrant protestors overwhelmed garda lines in Westmeath to access an asylum seeker accommodation centre.
Gardaí say there were around 200 people involved in the demonstration, which took place on Sunday in Athlone.
A small number of those gained entry to the site, with one security guard being injured in the process.
A generator was subsequently damaged leaving those staying in the accommodation centre without power for a time.
Athlone Fine Gael Councillor John Dolan is part of a group of local representatives who are taking a high court action against the Department of Integration over the Lissywollen site.
He says what happened last weekend was a step too far: