Protesters at the Kepak meat factory in Athleague, Co Roscommon, have blockaded a truck leaving the factory.
Video footage obtained by RTÉ News shows some protesters with their heads and faces covered, while one person is seen wearing a balaclava.
The incident occurred this morning as three refrigerated lorries were leaving the facility.
Protesters stopped the third lorry leaving the plant.
Gardaí arrived at the scene earlier this afternoon and spoke to the protesters.
A High Court order granted earlier this week prohibits such activity taking place outside meat plants.
Further incidents were reported yesterday as gardaí were called to a plant in Co Cavan when a protester drove a tractor towards a wall.
Gardaí also attended an altercation at Kildare Chilling near Kildare town when a protester climbed on top of a truck cab.
Meat Industry Ireland has said 12 meat plants have ceased operations as a result of the ongoing protests.
It said its members have had to lay off staff and have suffered significant losses as a result of the pickets outside meat factories.