At around 11.40pm on Saturday 5 September 2015, police were called to Bowker Vale Metrolink stop following reports of an assault.
Three men had approached a group of four men who were waiting for a tram and verbally and physically assaulted them.
A 17-year-old man was the victim of a Section 18 assault and remains in hospital with serious head injuries.
Two 18-year-old men were the victims of a Section 39 assault, while a 20-year-old man was the victim of a Section 47 assault.
Police are treating the assault as an anti-Semitic hate crime and are appealing to anyone with information to come forward.
Detective Inspector Liam Boden of North Manchester division said: “I know this will cause upset and anxiety in the Jewish community and I want to offer reassurance that we have launched an investigation to find the people that did this.
“This attack is being treated as a hate crime and I want to send the message that hate crime will not be tolerated and we will do everything we can to stamp it out.”
Metrolink services between Manchester and Bury were partially restricted but all are now running.
Anyone with information or if you believe you are the victim of, or witness, a hate crime should call police on 101, or the independent charity Crimestoppers, anonymously, on 0800 555 111.
