The reports said a 57-year-old man had been detained after the shooting, which happened at a bar in the Fidene district where the meeting was being held.
"He came into the room, closed the door and shouted 'I'll kill you all' and then started to shoot," Italian news agency Ansa quoted a witness as saying.
Four other people were wounded in the shooting, with at least one of them suffering serious injuries, Reuters reported.
The suspect was a local man who had been in a series of disputes with the residents' association, another witness told Rai News.
MNA/PR