A “defenceless” 65-year-old man was left in a critical condition after being attacked by two teenagers.
Police are investigating the assault at Stockport Interchange at about 21:45 BST on Tuesday.
No arrests have yet been made and Greater Manchester Police is appealing for information as a search for the suspects continues.
Det insp Shifa Chowdhury said: “This is a sickening attack by what we believe was two teenagers which left the victim, who was defenceless, with serious injury.”
She said the force believed members of the public were in the area at the time.
“Now is the time to come forward and do the right thing. No one deserves to see a family member or loved one be attacked in this way,” she added.
