Blaze comes after historic Rome bridge went up in flames two nights ago.
Around 30 buses belonging to Rome municipal transport company ATAC were destroyed in a massive fire in the early hours of Tuesday 5 October.
An investigation is underway into the circumstances surrounding the fire which broke out before dawn at the bus depot on Via Prenestina.
ATAC said in a statement that the fire involved "20 older vehicles, with varying degrees of damage" and that nobody was injured in the blaze.
Firefighters, who arrived on the scene at 04.15, referred to "around 30" buses, tweeting three hours later that the flames had been extinguished.
The incident comes two days after the historic Ponte di Ferro in Ostiense was severely damaged by a fire on the eve of local elections in the capital.
It is not the first time that fires have occurred at a bus depot in Rome in the middle of the night: three buses were destroyed at Grotta Rossa in August and seven buses went up in smoke in June 2020 at the Magliana depot.
Buses in Rome are also known to catch fire while in service, a phenomenon known by Romans as 'Flambus', with poor maintenance and ageing vehicles cited among the factors.
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