A trio of vicious robbers terrorised Manchester's Northern Quarter as they commmitted seven robberies in just 90 minutes.They got a taxi into town at 2am before targeting vulnerable revellers at the end of their night. The thugs surrounded their victims and attacked them with punches, stamps and kicks before fleeing with their valuables.They inflicted serious injuries.Victims were left with fractured jaws, damaged vertabrae and broken ribs.