An Egyptian teenager who died after being attacked by a gang in Nottingham, UK, may have been the victim of mistaken identity, her family said. Engineering student Mariam Moustafa, 18, was left in a coma after being attacked by 10 girls in the central England city on February 20. Police said she was "punched several times" in the street by a group of "threatening and abusive" women who then followed her onto a bus. She died of her injuries last Wednesday, prompting outrage in Egypt and Italy, where she was born and grew up. Prosecutors in Rome have now opened an investigation into her death, Italian media reported. Her family initially claimed the assault was a hate crime, but their latest comments suggest they now think she was mistaken for another woman, posing as “Black Rose”. Her 16-year-old sister, Malak, told the <em>Nottingham Post</em> on Sunday that she believes the mob of girls could have confused Mariam with a similar-looking girl who had been fighting with them on social media. “They called Mariam 'Black Rose' because someone on social media with that name had been arguing with them,” Malak said. "But Mariam said it wasn't her, and they called her a liar and started to attack her." A post-mortem examination into Mariam’s death was “inconclusive”, and police said that more tests will be carried out to determine whether there was a connection between her attack and her death three weeks later. A 17-year-old girl has been arrested on suspicion of assault occasioning grievous bodily harm and released on bail. Moustafa's death has caused anger in Egypt, notably on social media. Partial footage of the attack, filmed at the back of the bus, has been circulating on social media. _______________ <strong>Read more:</strong> _______________ Cairo's embassy in London said the "deep concern of the Egyptian public is evident" and called for those responsible to be "brought to justice swiftly". Italy's foreign ministry on Sunday also called for swift action over the "atrocious" mob attack. "In relation to the tragic case of compatriot Mariam Moustafa, brutally killed in Nottingham, we express our deep condolences and sympathy to her family, and additionally wish that those responsible for this atrocious crime are soon brought to justice," the foreign ministry said in a statement. The Rome prosecutor has asked British authorities to share details of the investigation, and authorities in Egypt have also asked UK officials for more information about the investigation. British foreign secretary Boris Johnson said on Friday that he was "deeply saddened by the death". "My condolences to Mariam's loved ones. I have assured Egyptian foreign minister [Sameh] Shoukry that Nottinghamshire Police are investigating the case," said Mr Johnson. Nottinghamshire Police said it was treating the attack "very seriously" and was "working hard to establish the circumstances". The teenager's father Mohamed Moustafa, 50, said: "I want justice for my daughter – not just my daughter but also so this doesn't happen to another girl or another boy. "My daughter was like an angel. She would do anything for anyone. "She meant the world to me."