Northern Ireland's police chief has blamed the paramilitary Ulster Volunteer Force for issuing threats to four Catholic families in a cross-community housing development in Belfast.
George Hamilton said the East Belfast UVF was behind the intimidation of the families in Cantrell Close neighbourhood.
The clear attribution comes following a week of growing pressure on the police to confirm who it believed was behind the threats.
"There are people using the guise of the UVF who we believe are members of that organisation who are threatening people because of their community background, because of their religion, to leave their home - that is not acceptable," said Mr Hamilton.
The Police Service of Northern Ireland chief constable said the UVF was so "chaotic" the police was not yet sure whether the threats were supported by the leadership of the criminal organisation, or were made by individual members.
"We are of the view that there's people purporting to be of East Belfast UVF who have been behind those threats," he said.
"Whether or not that is an organisational position we don't know because it is a chaotic disorganised crime group.
"They have no legitimacy, they are a scourge on the community."
Cantrell Close, off the Ravenhill Road in the south of the city, was supposed to be a flagship cross-community development as part of the Stormont Executive's Together Building United Communities programme.
Mr Hamilton vowed to take tough action against the East Belfast UVF but expressed frustration that witnesses and individuals with information were not willing to give formal statements through fear of the organisation.
"We are going to make life difficult for them because they are a scourge on that community," he said.
The police chief noted that the social housing development was supposed to be an example for shared living.
"What an irony that is," he said.
Following the intimidation of the Catholic families, two Protestant community workers living nearby, both pensioners, were also threatened this week.
Mr Hamilton said it was too early in the investigation to say whether dissident republicans were to blame.
"This has only just emerged in the last 24 hours, people want us to jump to conclusions, we are police officers, we go where the investigation takes us - we don't know about that yet," he said.
"But whatever the source of any of these threats or intimidation, it is not acceptable - we are a society that should be moving on and living together."
The Cantrell Close development was hit with another controversy in the summer when loyalist paramilitary flags were erected on lamp-posts.
A loyalist community group in east Belfast said those flags had now been taken down as a gesture of "goodwill" and in an attempt to de-escalate tensions in the area.
Mr Hamilton was asked whether the continuing lack of powersharing government in Northern Ireland was creating a vacuum that paramilitaries were exploiting.
He said a functioning executive would help create a more "stable" society and encouraged the North's politicians to strike a deal to restore a Stormont executive.