Police in Italy have arrested two American students.
They the pupils are connected to the killing of a policeman in central Rome.
According to a statement from Italian military police Carabinieri, the students are also being held for attempted extortion.
The students allegedly stabbed 35-year-old Mario Cerciello Rega to death on Friday.
Another police officer was injured in the incident.

Trump says Iran ceasefire 'on life support' after he rejects Tehran's response
India's Modi to begin five-nation tour, including UAE
EU ministers agree on sanctions targeting violent West Bank settlers
Last six passengers leave Hantavirus-hit ship as captain hails their patience
Suspect in Trump attempted assassination pleads not guilty
UK's Starmer promises to be bolder to try to rescue his job
Philippine lawmakers to vote on impeachment of presidential hopeful Duterte
Six people found dead in boxcar in Texas, police say
