An elderly man was thrown to the ground after chasing two strangers from his garden.
The 84-year-old man was sitting at the rear of his property in Cold Ashby Road, Guilsborough, on Saturday July 30.
At about 3pm he saw two men in the back garden. On seeing him, they ran to the front of the house.
The victim then chased them to their vehicle, a red hatchback, possibly a Peugeot 206, with a registration number starting HY02.
The victim approached one of the offenders in the car, who then got out and threw him to the ground, causing the man pain to the chest and cuts to his right elbow.
The offenders are both described as white, about 25 years old and around 5ft 10in.
One had a stocky build, a pale complexion and was wearing dark woollen clothing and black boots.
The other had a skinny build and wore lighter coloured clothing with patches of red on it. He spoke with a Northampton accent.
The two men made off in the car towards Guilsborough village.
Officers would like to speak to anyone who may have witnessed this incident or who may have any information regarding it.
Witnesses or anyone with information is asked to contact Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 111 555.