Officers are appealing for witnesses and information after a man was attacked in Hounslow.
Police were called to Hounslow Heath, Hounslow at 16:35hrs on Tuesday, 29 October following reports of a noxious substance attack.
Officers, the London Ambulance Service and London Fire Brigade attended and found a man aged in his 30s, suffering from facial injuries and slash wounds to the upper body.
He was treated by LAS before being taken to hospital; his condition is not life-threatening.
The victim was approached by three males who attacked and robbed him.
No arrests have been made at this stage. The incident is being treated as a robbery.
Officers ask anyone with information to call 101 ref CAD 5065/29 Oct.