Thames Valley Police is appealing for witnesses to an aggravated burglary in Iver.
Two men forced entry by a rear door in to a property on Syke Cluan at around 7.10pm on Tuesday (5/12).
Three victims, a woman and a man in their fifties and a woman in her eighties, were threatened with a spade and knife and the offenders demanded money.
When the offenders left the property they all got in to a vehicle.
Two of the victims were assaulted and one victim, the man in his fifties, sustained arm injuries but did not require hospital treatment.
No property was stolen.
The two men are described as between 5ft 7ins and 5ft 11ins tall, they were all wearing dark clothing and had their faces covered with balaclavas. They spoke with Eastern European accents.
Investigating officer, Detective Constable Victoria Bygrave of Force CID in Aylesbury, said: “There are likely to be more patrols in the area following this incident while further investigations take place.
“If you have any questions, please feel free to approach officers.
"A thorough investigation is underway.
“If you have details you think could help with our enquiries, please contact police.”
If you have information about the incident please report this via the non-emergency police number 101 quoting reference 43180371259 or contact us online.
If you do not wish to speak to police, please contact the independent charity Crimestoppers on 0800 555 111.