Forty people living in two adjoining houses in Dublin city centre have been told to leave immediately.
The Brazilian students were offered €250 to get out, and given two hours to pack up their belongings.
Aisling Bruin, a volunteer with Dublin Central Housing Action group, says the tenants do not know who their landlord is.
"There's different people calling up to the house that won't give their names or identify themselves," she said.
"Initially they were saying that the tenants needed to pack their bags and they gave them two hours to do so and offered €250 for them to leave.
"Then a very intimidating group of of people came to the house with drills and different tool.
Dublin Central Housing Action said the tenants had contacted them in February in connection with eviction threats and after asking local residents they found that landlords weren't giving written notice of eviction to tenants and tenants were paying up to €400 to share a room with up to four other people.
Yesterday morning, a fire inspection had taken place and the buildings were ordered to be vacated.
The tenants contacted the group again yesterday and said that they wanted outstanding rent and deposits paid back promptly and a suitable alternative home sourced.
However, when "a number of unidentified men" who claimed to represent the owner, showed up at around 6pm, they spoke to tenants individually and offered them cash to leave immediately.
"At 10pm the owners representatives said time was up for the tenants.
"At this point Gardaí and Public Order Unit began arriving along with the Fire Brigade. The Gardaí said they were told properties needed to be evicted due to health and safety."
However, the group managed to get an agreement for 20 tenants to stay in the property for another seven days with fire marshals appointed.
Dublin Central Housing Action said: "The Fire Inspectors advocated strongly that the tenants must have their money returned to them and further noted if tenants had to leave that the owner is primarily responsible for providing suitable alternative accommodation."