Four buildings were evacuated as a precautionary measure, with 130 families affected. People in the area were instructed to keep doors and windows closed and to wear masks outside.
"It's now clear that Rome is being attacked by pyromaniacs," Claudio Mancini, an associated of Mayor Roberto Gualtieri, said.
The city administration and the new mayor are believed by many to be the target of the deliberate fires.
"Whether these are individual acts or the actions of organized crime, the investigations will reveal," Mancini said.
