The man and woman had an iPhone taken as they walked on a footpath near Riverview on Tuesday at around 11.15pm.
One of the men demanded their mobile phone and another threatened them with a knife.
The first suspect is described as being black, around 5ft 9ins, aged in his early to mid 20s, of a medium build and was clean shaven with short black curly hair.
The second suspect is described as being black, around 5ft 9ins, aged in his early to mid 20s and is clean shaven with short black curly hair.
The third suspect is described as being white, around 5ft 11ins, aged in his early to mid 20s and wore a grey and white scarf covering his face so only the eyes could be seen.
Anyone with information is asked to call Grays CID on 101 quoting crime reference 42/144159/18 or Crimestoppers anonymously on 0800 555 111.
Tags: Grays
