Two attacks on men in Corby, one a pensioner, are believed to be linked.
They happened in the Willow Brook Road area on the same night as the victims were walking home.
A robbery happened at about 10pm on Saturday, October 6, when a 71-year-old man was hit from behind and knocked to the ground in Orkney Walk.
Cash and other items were taken from his pockets and he suffered facial injuries.
Later, between 12.30am and 12.40am, a 50-year-old man was walking in the Willow Brook Road area when he was hit from behind and pushed to the ground, leaving him with injuries to his face.
Witnesses, or anyone with information, are asked to call the police on 101 or Crimestoppers on 0800 555 111.