Two men broke into a house and assaulted the homeowners, leaving one with a broken arm.
The men broke into the property in Hall Park Lane, Rushden, shortly after midnight on Saturday and made their way to a bedroom, where they threatened the 63-year-old man and 35-year-old woman, demanding money.
During the course of the incident the male victim was assaulted and sustained a broken arm.
The offenders forced the woman into the kitchen and again demanded she hand over cash. There was no cash in the house so the offenders stole a wallet and fled the property.
They were both about 5ft 9ins, of slim build and wore dark coloured clothing, with their faces covered and hoods up. They possibly spoke with Asian accents, according to police.
Police would like to speak to anyone who may have information about this incident or who may have seen two men in the Hall Park Lane area of Rushden acting suspiciously in the early hours of Saturday.
Witnesses or anyone with information can call police on 101 or Crimestoppers anonymously on 0800 555 111.