Police investigating a 15-year-old boy's fall from a shopping centre footbridge have released four of five teenagers arrested.
Greater Manchester Police said the boy remained in a critical condition in hospital after falling from the covered walkway at the Trafford Centre at about 8.15pm on Saturday.
The force said initial inquiries suggested he may have been involved in an altercation with a group of youths, but officers no longer believe this is the case.
Five 15-year-old boys were arrested on suspicion of assault on Saturday and four have since been released with no further action. One is helping officers with their inquiries.
Detective Sergeant Stephen Warriner said: "This is a tragic incident which has left a boy fighting for his life in hospital. My thoughts are with his family who are understandably beside themselves at this awful time.
"Since yesterday we have been analysing CCTV and speaking to witnesses to try and understand exactly what happened.
"But I would urge anyone who might have seen anything to please contact us immediately.
"We know this boy was in the shopping centre with a group of other boys before they went outside, where he sadly fell.
"If you remember anything from that evening, no matter how small, I implore you to get in touch."
Anyone with any information should call police on 0161 856 7525 quoting incident number 2045 of 28 October 2017.