The Housing Executive says some of its workers have been threatened in New Lodge area of north Belfast.
The alleged victims, who include contractors and staff, are understood to have been conducting maintenance work on social housing.
The Housing Executive has condemned the threats and reported them to police.
In a statement, a spokesperson said they were are of "specific threats" made to staff and to a contractor in the New Lodge area of North Belfast.
"We utterly condemn this threat," the spokesperson said.
They added: "The Housing Executive takes these matters very seriously, and the safety of people who work for us is paramount.
"We are now reviewing the provision of services to the blocks.
'War with the community'
"We are calling for this threat to be withdrawn immediately and are currently seeking assurances from local community representatives."
Sinn Fein MLA Carál Ní Chuilín said the threats should be lifted immediately.
"I totally and absolutely condemn these cowardly threats against Housing Executive staff and contractors working on the Seven Towers in the New Lodge area.
"These threats have led to work being stopped which means residents are being kept in fuel poverty by the actions of those responsible.
"Those behind these threats do not have the support of the local area and in fact at war with the community."
The police said they do not discuss the security of individuals, but said if they receive information that a person's life being at risk they will inform them accordingly and never ignore threats.