They said the group of “North Africans” were chasing church-goers, scaring children and putting the area “under siege”.
They also said a collection box at the church in Italy had been forced open – sparking a furious reaction from Father Francesco Inversini.
He said the migrants, sheltering in a building near the church of Cristo Re in Milan were “free to do” anything.
Father Inversini said in a letter to the police: “They are illegal, no one controls them, they are free to do what they please.”
The church’s administrator, who only wanted to be identified as Tommasso for fear of reprisals, went further.
He warned the migrants were part of an ongoing crime spree in the area – and claimed the church’s staff could be lynched if police do not do anything.
Tommasso said: “I do not say my name because those guys can kill me, but here, parents and parishioners are angry.
“They scare children and they chase people after they go to church to ask for money. We can’t live like that.
“The peace in the neighbourhood is gone, we are under siege. They come and go, they have no documents, they bother people and they smash car windows.
“We can’t wait for them to come and lynch us without letting authorities know what’s going on.
“But we also have to take care of our poor people in Italy. I understand that the pastor asks for police intervention.”
In response to criticisms of his letter, Father Inversini later added: “People are worried because they do not know what comes next. Recent events create suspicion and anxiety in the population.
“In the name of the inhabitants – urges the pastor in the complaint to the police – I consider it appropriate to report and request an intervention of the competent authorities to clarify and resolve a situation that can become uncontrolled and create uncontrollable reactions.”