A woman had her mobile phone grabbed from her hand as she was walking in The Drapery, Northampton, sometime between 4.40pm and 5pm on Saturday, January 7.
The victim was approached from behind by a man who tried to grab the phone from her hand. After a struggle, he made off with the phone along Bradshaw Street.
The offender is described as a black male, around 5ft 10ins tall and of slim build. He was wearing a black coat with a furry hood worn up, black jogging bottoms and black trainers.
Anyone with information can contact Northamptonshire Police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.