ROME (Reuters) - A passenger bus caught fire and exploded in the heart of Rome on Tuesday, while another bus was gutted in the suburbs later in the day, highlighting the dire state of public transport in the Italian capital.

Slideshow ( 5 images )

The twin blazes, both believed to have been caused by mechanical problems, brought the number of Rome buses destroyed by fire so far this year to 10. Some 20 buses operated by local transport company Atac were burnt out in 2017.

The drivers of both buses on Tuesday managed to escape with their passengers unscathed, although a women who worked in a nearby shop suffered minor burns when one of the two vehicles subsequently exploded in central Rome.

The number 63 bus came to a halt near the Trevi Fountain, a popular tourist attraction, before the fire took hold. Video showed flames shooting into the sky and the facades of the two nearest buildings were left smeared with black soot.

Less than four hours later a school bus also operated by Atac caught fire in a southern suburb.

Politicians were quick to blame mayor Virginia Raggi and her party, the anti-establishment 5-Star Movement, for the series of fires, saying it showed they were incapable of governing Rome.

“Romans risk getting hurt every day with this 5-Star administration,” said Barbara Saltamartini, a member of the far-right League party. “These images are being seen around the world and they are the latest images of Raggi’s failure.”

5-Star says it inherited a transport system that was mired in debt and dragged down by poor management and that it is working hard to overcome numerous long-standing problems.

A former head of Atac said last year the company was suffocating under some 1.3 billion euros ($1.54 billion) of debts and should declare bankruptcy.

According to an internal Atac report, 36 percent of all the company’s buses are in garages because they have broken down or are undergoing maintenance, with the figure rising to 50 percent for the city’s creaking fleet of trams.

Atac’s woes reflect broader problems aflicting the city’s infrastructure. Many of Rome’s roads are riddled with potholes after a particularly cold, wet winter, while almost 50 sinkholes have opened since the start of the year.