Signs that include an anti-immigrant message have been erected in a largely loyalist estate in Newtownabbey, north of Belfast.
The signs calling for "locals only" and refers to "no longer accepting the rehoming of immigrants" were put up in the Rathcoole estate, the latest incident after similar messages were posted in a south Belfast estate and a small town outside Dungannon.
The Housing Executive and private landlords were told to "take note", while action would be taken against anyone removing the posters, those behind their erection warned.
Posters, placed on railings and lamp posts through the estate, refer to what is described as "illegal immigrants".
Police said they are aware of posters erected in West Crescent in Newtownabbey within the last few days. Their erection is being treated as a hate incident and police are in contact with local community representatives.
Meanwhile, more than 100 people attended a protest outside two blocks in the Belvoir estate in south Belfast over the lack of social housing in the area.
Attendees were protesting about what they say is an inadequate supply of social housing for the local community.
Windows and doors of one of the tower blocks were smashed while a Housing Executive worker was threatened by two masked men last week.
The incidents came around the same time as threatening posters were put up warning against any re-housing of "illegal immigrants" in the Belvoir estate.
The posters also referred "excrement of other communities", which local residents say refers to the housing of what are broadly characterised as undesirable elements.
Ahead of the protest, the Belvoir Area Residents Group posted a message on social media stating that it had been made aware of a protest. It was not involved with organising the protest.
"While we understand the frustrations around the lack of social housing and the proposal that had been put forward by NIHE, we would ask that everyone attending remains calm and respectful," it said.
Rumours circulated that asylum seekers were to be housed in flats in the tower blocks, where tenants have been moved out of as both are slated for demolition. The NIHE said it had been considering using five of the vacant flats, but they would have been people "probably with a connection" to the estate.
NIHE chief executive Grainia Long said the proposed temporary tenants would most likely have been placed in the flats because Belvoir was their area of choice.
Following a meeting with the NIHE. local DUP councillor, Sarah Bunting, said the delegation had received "confirmation that there will not be any allocations into those flats at this time".
In Moygashel in Co Tyrone, a poster topped by an image of a Red Hand flag was erected. It stated: "It is not racist to protect your own community."