A car has been badly damaged in the incident, which occured on Via Marmorata, in the centre of the city.
Reports suggest the damage was caused by a parcel bomb, although this is yet to be confirmed by authorities.
Police have confirmed two blasts at the same scene – one larger than the other.
According to reports in Il Giornale, the blasts were likely to have been the result of two rudimentary homemade bombs filled with flammable liquid.
The explosions occurred near the side entrance of a post office in the Aventino neighbourhood.
Local media claims the explosive devices were placed between vehicles in the post office car park.
Police, bomb squads and sniffer dogs are at the scene, and the area remains cordoned off.
Information service Luceverde, run by the Italian Automobile Club in collaboration with city police, said on Twitter that ‘technical checks’ were being carried out near the post office.
Franco Zelinotti, duty officer for the fire service, said the devices appeared to have been place inside a plastic box, and confirmed that there had been no injuries.
The post office was open at the time, with reports suggesting a high volume of customers and clerks present.
The prosecutor of Rome has opened an investigation into the incident.
A secondary bomb alert had been issued for the Piazza di Porta Capena – just streets away from the UN’s Food and Agriculture Headquarters – police and bomb disposal experts were deployed but have since been stood down and the incident deemed a false alarm.
News of the blast comes just weeks after Prince Charles visited the UN Food and Agriculture Organisation building in Rome.
The Prince was joined by the Duchess of Cornwall for a series of engagements in the Italian capital, which included a meeting with the country’s Prime Minister Paolo Gentiloni.
THIS IS A BREAKING STORY – REFRESH FOR UPDATES.