Windows and doors of a tower block in south Belfast were smashed while a Housing Executive worker was earlier threatened by two masked men.
Information on the incidents emerged after 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.
Rumours have circulated in the estate that two tower blocks listed for demolition, Belvoir and Breda, would be used to house asylum seekers.
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The attack on the tower block, which happened on Thursday night, was described by NIHE's chief executive Grainia Long as an "attack on the safety and security of people's homes".
“On Thursday night, windows and doors at Belvoir House were smashed. One of our staff and tenants were in the building when this attack occurred," Ms Long said.
“I am appalled that anyone would think it is acceptable to attack the homes of people who have lived in this area for years and also attack the provision of a vital service to the local community - a service that provides safety and support to the residents of the tower blocks.
“This is an attack on the safety and security of peoples’ homes.
“The safety of our staff and tenants is our priority and we are now reviewing service provision in the area. We are also providing support to our staff.
“We have reported this incident to police.”
Earlier, Ms Long said staff and tenants were in the building when the attack happened.
But Belvoir House is largely empty as most of the residents have been already re-housed.
Earlier in the week, a NIHE worker was threatened by two masked men. It was reported on Friday that elements of the UDA have been involved in the incidents.
Rumours that asylum seekers will be housed in the blocks have been circulated among residents in the estate. South Belfast MLA Edwin Poots alluded to those rumours in an interview on Wednesday evening.
Donal Lyons of the SDLP, who represents the Balmoral DEA, removed posters from lampposts on Tuesday. Graffiti then emerged telling the representative to stay out of estate.
The NIHE said it had been considering using a very small number of two-bedroom flats in the blocks for short-term accommodation "for local households".
In a statement to the Irish News on Thursday, Ms Long said the moving of people out of the two tower blocks "is ahead of schedule" and that following the demolition, new social housing will be built.
However, she added that due to the "unprecedented level of demand for temporary accommodation" NIHE has been "exploring ways of expanding the number of units available for those seeking assistance".
