Officers are appealing for witnesses after a man was robbed in Lynn on Friday (July 14).
It happened between 7.30pm and 8.30pm as the victim, a man in his 30s, walked along the alleyway which leads from Norfolk Street to the Albert Street car park.
The victim was approached from behind and hit with a weapon, thought to be a metal chain, which caused swelling and a cut above his eye.
During the incident about £90 in cash and an iPhone was stolen.
Officers are keen to hear from anyone who may have witnessed the incident or noticed anyone acting suspiciously in the area between the times stated.
Witnesses should contact Det Con Larissa Foreman at Lynn CID on 101 or call Crimestoppers anonymously on 0800 555 111.