A man in his 40s was out for a run in Meadowgate Lane, Wisbech when he was approached by two men who stole his torch and then assaulted him.
The two men then fled the scene on foot and the man was taken to hospital for treatment.
Both men are described as white, aged in their early to mid-20s, of slim build and were wearing dark coloured tracksuits at the time of the assault.
Police said: "We were called at 6.07pm yesterday (Monday December 9) with reports of a robbery."
An investigation has been launched and anyone with information should call police on 101 or visit www.cambs.police.uk/report, quoting crime reference number 35/87938/19."
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