A woman had a knife held to her throat after she disturbed two men in the back garden of her house.
The woman spotted the two men in the back garden of her house in Kingsland Avenue, Kingsthorpe, Northampton.
The men got into her house, grabbed her handbag and held a knife to her throat.
She managed to run out of the property and call for help.
A spokesman for Northamptonshire Police said: “A member of the public then grabbed one of the attackers, but the two eventually fled the scene in a car.”
Both men were about 6ft 2in, slim, and wore dark clothes with hoods drawn tightly across their faces.
Officers investigating the case are particularly keen to speak to the person who challenged the men outside the house.
The incident happened at some point between 6 and 7pm on Tuesday May 13.
Witnesses or anyone with any information about this incident can call the police on 101 or Crimestoppers anonymously on 0800 555 111.