ROME -- A section of the Torre dei Conti, a medieval tower undergoing restoration in central Rome, collapsed on Monday, injuring four construction workers and prompting an emergency rescue operation, local media reported.

The collapse occurred during renovation work. A second partial cave-in took place while firefighters were carrying out rescue operations, releasing a large cloud of dust but causing no further injuries among emergency crews, Italy's Ansa news agency said.

Four workers were involved in the incident. A 64-year-old man was rescued alive from the rubble and taken to hospital in critical condition with head injuries, while another worker remained trapped but conscious, according to health sources. Two other workers sustained minor injuries and declined hospitalization.

Firefighters dispatched three teams, two ladder trucks, and specialized rescue units to the site. Pedestrian and vehicle access to the surrounding area has been restricted to facilitate ongoing rescue and safety operations.

An investigation into the cause of the collapse is underway.