Firefighters worked through the night to tame a blaze in Castel Fustano, a nature reserve on the Lazio coast. Traffic was temporarily blocked and some homes evacuated on Monday evening as the flames tore through the pine forest south-west of the capital.
Rome mayor Virginia Raggi said the wildfire was "a very serious situation".
"We need the help of the region and the government. Rome can not be left alone in the face of this environmental disaster. We must all work together," she said.
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Lazio's regional president, Nicola Zingaretti, had on Monday called for the government to declare a state of emergency over the recent spate of wildfires which have affected the entire country but the southern regions in particular.
A 22-year-old man was arrested for suspected arson in connection with the Castel Fusano blaze, according to Rai News, after police reportedly found him burning tissues in the area.
Italy's fire service said on Tuesday that the majority of the fires they have tackled this summer were started "through arson or stupidity".
In addition to the Lazio man, police have also arrested suspected arsonists in Teggiano in Salerno, Agrigento in Sicily, and on the south-east coast of Lecce. All three are believed to have started fires in nearby national parks.
A Naples man was reported dead as a result of the fires on Monday, the first casualty in Campania after two men were killed in Calabria the previous week. The latest victim was a 53-year-old businessman and former councillor, La Repubblica di Napoli reported, who died after climbing onto the roof of his shed in an attempt to escape the flames.
Several homes were evacuated in Naples as a fire raged in the southern Posilipo neighbourhood of the city, totally destroying one deserted house.
Campania's regional governor on Monday called Italy's Defence Ministry to ask for further assistance of the army, who have been deployed in the Mount Vesuvius National Park for several years to help Civil Protection volunteers and firefighters.
And in Tuscany, around 15 houses in Volterra were evacuated while firefighters tackled further major fires in Grosseto - where the mayor described the suspected arson attacks as "war" - and Piancastagnaio further south.
In Pistoia, midway between Lucca and Florence, one firefighter was taken ill after working a 20-hour shift. He was later released from hospital in a stable condition.
Italy's firefighters have had their work cut out this summer as the number of wildfires has increased significantly compared to the same period in 2016.
While police suspect arsonists are behind a large proportion of the blazes, Italy's dry weather after months of low rainfall, together with strong winds, have allowed the flames to spread quickly.
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Photo: Conrad Dietrich Magirus Award/Magirus Group