A man was threatened with a knife and forced to hand over valuables in Newmarket on Wednesday.
Two balaclava-clad men approached a man in Green Road and demanded that he hand over any valuables at around 6:50pm. His rucksack was searched and a letter stolen.
The two men, who were also wearing gloves, walked off along Green Road onto The Avenue after the robbery.
Anyone who witnessed the incident, saw anything suspicious in the area of has knowledge of the incident should contact Bury St Edmunds CID on 101, quoting crime reference 37/77958/17 or call Crimestoppers anonymously on 0800 555111.