The fire services reported on Saturday that the fire was under control. Around 100 firefighters in 50 vehicles were deployed, including a specialist fire engine from Ciampino Airport.
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.