Two US citizens are currently in police custody in Rome over the death of a Carabinieri police officer, Italian media reported on Friday.
One of the suspects later confessed to stabbing the officer, reported the Adnkronos and ANSA news agencies, citing investigators. Police earlier described the main suspect as having a North African background.
The two men were questioned at Carabinieri headquarters over the death of 35-year-old Mario Cerciello Rega, who was fatally stabbed in Rome’s central Prati district near the Vatican early Friday morning.
Investigators did not immediately say why the second suspect was being held.
Cerciello Rega and other officers were involved in a plainclothes operation against two muggers at around 3 a.m. local time.
The muggers had stolen a wallet and mobile phone from a man, later saying they would return his belongings in exchange for €100 ($110).
The man reported the crime and attempted extortion to the police, and set up a meeting point with the thieves.
Police showed up to the meeting instead, but were attacked with a knife. Cerciello Rega sustained multiple stab wounds and later died of his injuries in hospital.