A man was assaulted by a group of teenagers on Palatine Road, Northenden.
At about 5.50am on Friday 16 March 2012, a 58-year-old man was walking down Palatine Road.
As he neared the golf club he was approached by five youths, described as white and between 16 and 18 years old, of average height and wearing dark clothing.
One offender punched the man in the head and another produced a knife. The man fell to the ground and the group ran off.
Detective Constable Paul Jackson, of West Didsbury CID, said: “This was a needless and unprovoked attack on a man who was out walking alone.
“I am appealing for the public’s help to identify this group of teenagers who have been armed with a knife and are clearly prepared to use violence.
“Perhaps someone you know was out all night or left the house in the early hours? If so I am keen to hear from you. If you have any information whatsoever please get in touch.”
Anyone with information is asked to call police on 0161 856 6153, or the independent charity Crimestoppers, anonymously, on 0800 555 111.