A man in his 70s was pushed over and robbed of £20 in Kettering.
The incident took place in Bath Road between 7.15pm and 7.30pm on Sunday, December 16.
The victim was walking along the road when he was approached by two men.
They grabbed his umbrella before pushing him to the ground.
They then searched his pockets and took a £20 note before running off.
A police spokesman said there had been no arrests and that they had no confirmed descriptions of the attackers.
The spokesman appealed for witnesses or anyone with information about the robbery to contact them on 101 or Crimestoppers anonymously on 0800 555111.