Police are hunting four intruders wearing balaclavas who broke into a home in Camberton Road, Linslade on Thursday at 2.4opm.
After getting in by breaking a window, they were disturbed by the homeowner.
They demanded money and fled with a purse down Cedars Way towards Wing Road.
Officers carried out a search of the area and the helicopter was called out but the men, who are described as being in their late 30s/early 40s and “unfit” escaped.
One had a brown baseball cap and beige jacket and the others wore dark clothing.
Call police on 101 with any information.