One worker has been rushed to the hospital with serious injuries, and another is trapped under rubble following the partial collapse on Monday of a medieval tower in the heart of Italy's capital, near the famous Roman Forum ruins.

"We are trying to get him out alive, but the situation is complex because of the risk of further collapses," national fire department spokesman Luca Cari told Reuters about ongoing rescue efforts.

Regional President Francesco Rocca, disclosed that the worker in hospital was not in a life-threatening condition, while two more workers suffered minor injuries and declined hospital treatment.

The 29-metre Torre dei Conti stands near one of the Eternal City's tourist hotspots. It is located halfway along the Via dei Fori Imperiali, the broad avenue that leads from central Piazza Venezia to the Colosseum.

Firefighters were on the scene on Monday when part of Torre dei Conti , a 29-metre medieval tower near the Colosseum in Rome collapsed, leaving one worker in hospital with serious injuries.

It suffered at least two collapses, according to videos posted on social media. On both occasions, clouds of dust came billowing out of the windows, along with the sound of collapsing masonry.

The second incident took place while firefighters were working on the structure with aerial ladders.

The building was still standing, but showing significant internal damage.

It once hosted city hall offices but has not been in use since 2006 and was being worked on as part of a four-year renovation project due to end next year, according to city authorities.

Due to the restoration work, the area around the tower was closed off to pedestrians.

The building was established by Pope Innocent III for his family in the early 13th century, and was originally twice as high, but was scaled down after damage from earthquakes in the 14th and 17th centuries.