A 19-year-old American foreign exchange student was stabbed 25 times in Rome's central Monti district at dawn on 1 November, following a night of Hallowe'en partying.

The victim was stabbed with a kitchen knife as he slept at their apartment on Via del Cardello, a small side street off the Colosseum-end of Via Cavour.

Another US student was injured while attempting to apprehend the alleged attacker, a 20-year old fellow American flat mate, who has been arrested on suspicion of attempted murder.

The victim underwent emergency surgery for a perforated lung and multiple stab wounds at the city’s S. Giovanni hospital. His injuries do not appear to be life threatening.

The flat is shared by five Americans, all students at one of the American universities in Rome.

It is believed that the students had been at a club in the Laurentina district before returning home where the party continued. Police discovered quantities of marijuana, cocaine and ecstasy powder at the apartment, and say the motive for the attack remains unclear.