A man suffered a fractured skull after being assaulted in Denton.
At about 3pm on Tuesday 21 August 2012 the victim, a 21-year-old man, was walking along Mancunian Road, Denton when he was hit by an unknown weapon, possibly a hammer, across the head.
The victim also suffered a black eye. He couldn't get a description of the offenders but did manage to get home before he was taken to hospital.
Detective Sergeant Claire Platt said: "It would appear as though this was an unprovoked attack which has left this man with serious injuries.
"I would urge anyone who witnessed this incident to call us."
Anyone with information is asked to call police on 0161 856 9309 or call the independent charity Crimestoppers anonymously on 0800 555 111.