One 15-year-old boy and an 18-year-old man were arrested on suspicion of murder.
16-year-old Kennie died in hospital on Saturday 22 January after suffering a fatal wound to the chest following a reported stabbing in Stretford.
Ten teenagers – aged between 13 and 17 – have already been arrested on suspicion of murder and have been released under investigation after being questioned by detectives.
Detective Chief Inspector Alicia Smith, from GMP’s Major Investigation Team, said: “These arrests are a considerable step forward in the investigation into Kennie’s death.
“Through meticulous inquiries we have now arrested all those we wanted to speak to in connection with the incident.
“Kennie’s family are being kept up to date by specialist officers of any advancements the investigation team make and will continue to be supported through this devastating time.
“We have spoken to over 100 people, collated in excess of 100 hours of CCTV and executed over a dozen warrants in a quest to bring Kennie’s family justice.
“Although it has been nearly a year since Kennie’s death, our work will not stop until we are certain that we have caught his killers. The case is proving to be complex, with multiple lines of enquiry explored.
“We are continuing to gather all available evidence to build a larger picture of the events in the lead up to Kennie’s death.
“I would like to use this opportunity to thank members of the public who have already shared information with us, – all it takes it one crucial piece of information that may be key to achieving answers for Kennie’s loved ones.”
