A man has been left with injuries to his eyes and face in a reported acid attack.
Officers found the victim after they were called to City Walk, near Silverdale Country Park in Salford, at about 14:00 BST on Friday.
The man, who is in his 20s, was taken to hospital for treatment but it is not yet clear how severe his injuries are.
Greater Manchester Police appealed for anyone with information to contact them.
Assaults involving corrosive substances have more than doubled in England since 2012, according to police figures, with the vast majority in London.
In a similar incident on Saturday, a man was injured in a suspected acid attack at a fish and chip shop in a seaside town in Kent.