Two US students have admitted stabbing a policeman to death in Rome after an alleged drug deal went wrong, Italian officals say.

Mario Cerciello Rega, 35, a deputy brigadier in the Carabinieri, was allegedly stabbed eight times while investigating the theft of a bag on Friday.

Two men are said to have snatched a bag from a drug dealer in Rome after he gave them a “different substance” instead of cocaine, according to an Italian investigator who spoke on condition of anonymity.

The thieves demanded a €100 (£90) ransom and a gram of cocaine in return for the bag, the Carabinieri said.

The alleged drug dealer then called the police and told them he had arranged a meeting with the thieves to get his bag and mobile phone back.

Italian policeman stabbed to death ‘by US students’ Show all 10 1 /10 Italian policeman stabbed to death ‘by US students’ Italian policeman stabbed to death ‘by US students’ Police in Italy say two 19-year-old US students have admitted fatally stabbing Carabinieri officer Mario Cerciello Rega to death in Rome on 26 July 2019. The policeman was investigating the alleged theft of a bag in what my have been a drug deal gone wrong, investigators say. EPA/Angelo Carconi Italian policeman stabbed to death ‘by US students’ epa07743590 Notes and flowers have been placed at the site where the Carabiniere police officer Mario Cerciello Rega was stabbed to death in Rome, Italy, 27 July 2019. A young US tourist has allegedly confessed to stabbing to death Mario Cerciello Rega, a Carabiniere police officer who was investigating the theft of a bag and cellphone before dawn on 26 July 2019. EPA/ANGELO CARCONI ANGELO CARCONI EPA/Angelo Carconi Italian policeman stabbed to death ‘by US students’ Italian policeman stabbed to death ‘by US students’ epa07741614 Carabinieri officers and forensic specialists investigate a crime scene where Carabinieri vice brigadier Mario Cerciello Rega was shot dead by robbers yesterday evening in Via Pietro Cossa, Rome, Italy, 26 July 2019. EPA/ANGELO CARCONI ANGELO CARCONI EPA/Angelo Carconi Italian policeman stabbed to death ‘by US students’ epa07741618 Carabinieri officer and forensic police work a crime scene where Vice Brigadier of Carabinieri Mario Cerciello Rega was shoot dead by robbers last night in via Pietro Cossa, Rome, Italy, 26 July 2019. Two men thought to be of African origins are being sought in connection with the stabbing to death over the night between Thursday and Friday of an on-duty Carabiniere police officer in the Italian capital. EPA/ANGELO CARCONI ANGELO CARCONI EPA/Angelo Carconi Italian policeman stabbed to death ‘by US students’ epa07743504 Andrea Varriale (L), the injured Carabiniere police officer, and colleague of slain Mario Cerciello Rega, in a Carabinieri car as he leaves a Carabinieri police station, in Rome, Italy, 27 July 2019. A young US tourist has allagedly confessed to stabbing to death Mario Cerciello Rega, a Carabiniere police officer who was investigating the theft of a bag and cellphone before dawn on 26 July 2019. EPA/CLAUDIO PERI - GIUSEPPE LAMI CLAUDIO PERI - GIUSEPPE LAMI EPA/Claudio Peri/Giuseppe Lami Italian policeman stabbed to death ‘by US students’ In this picture taken Friday, July 26, 2019 investigators are seen on the scene where an Italian paramilitary policeman was stabbed to death. A young American tourist has confessed Saturday, July 27, 2019, to fatally stabbing an Italian paramilitary policeman who was investigating the theft of a bag and cellphone before dawn Friday, (Angelo Carconi/ANSA via AP) Angelo Carconi Angelo Carconi/ANSA via AP Italian policeman stabbed to death ‘by US students’ A man leaves flowers in front of the Carabinieri station where Mario Cerciello Rega was based, in Rome, Saturday, July 27, 2019. In a statement Saturday, Carabinieri officers investigating the death Friday of officer Cerciello Rega, 35, said two American turists, both 19, have been detained for alleged murder and attempted extortion. (AP Photo/Andrew Medichini) Andrew Medichini AP/Andrew Medichini Italian policeman stabbed to death ‘by US students’ A woman gets emotional after leaving a note in memory on the spot where Mario Cerciello Rega was stabbed to death, in Rome, Saturday, July 27, 2019. In a statement Saturday, Carabinieri officers investigating the death Friday of officer Cerciello Rega, 35, said two American turists, both 19, have been detained for alleged murder and attempted extortion. (AP Photo/Andrew Medichini) Andrew Medichini AP/Andrew Medichini Italian policeman stabbed to death ‘by US students’ Sandro Ottaviani, commander of the station, stands near flowers left by Roman citizens in front of the Carabinieri station where Mario Cerciello Rega was based, in Rome, Saturday, July 27, 2019. In a statement Saturday, Carabinieri officers investigating the death Friday of officer Cerciello Rega, 35, said two American turists, both 19, have been detained for alleged murder and attempted extortion. (AP Photo/Andrew Medichini) Andrew Medichini AP/Andrew Medichini

Police say there was a scuffle at the agreed meeting point and Mr Cerciello Rega was stabbed eight times, dying a short while later in hospital.

CCTV cameras caught the two men running away with the bag and the two Americans were later found in a nearby hotel.

Police said the two students were “ready to leave” Italy when they were found.

The men, whose names have not been released, were arrested for alleged murder and attempted extortion and questioned overnight.

Police said officers found a long knife hidden in the panel of their hotel room during a search.

They also found clothes that the two men were thought to have been wearing during the attack.

A statement released by the Carabinieri said the two Americans admitted responsibility after being questioned by prosecutors and faced with “hard evidence”.

Mr Cerciello Rega worked as a deputy brigadier in the Carabinieri, Italy’s paramilitary police.

Interior Minister Matteo Salvini offered his condolences on Twitter, describing him as “a hero, a boy with all his life ahead”.

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Mr Cerciello Rega’s station commander, Sandro Ottaviani, said the policeman had only just returned from his honeymoon after getting married five weeks ago.

Colleagues and charities praised the generosity of the officer, who would often check on the homeless living in Rome’s main train station and helping to hand out meals and clothing.