A 77-year-old woman was tied up during a burglary at her home in Menston.
Police are appealing for information after three men barged their way into the house on Bingley Road when the victim went to investigate a noise outside shortly after 11pm on July 3.
The men tied her hands and searched the house, demanding to know where the safe was before taking jewellery and cash.
Among the jewellery was an expensive diamond bracelet.
They dragged the victim upstairs and threatened to hurt her if she did not tell them where the safe was.
She managed to set off a personal attack alarm which caused the men to leave.
The men tried to steal her car from the driveway but were unable to start it.
One of the group was described as being of large build and wearing grey tracksuit top and bottoms with one light stripe down each leg.
Another was wearing grey or light-coloured tracksuit bottoms, a black shiny jacket with a zip, and a light-coloured beanie hat.
The third was said to be slim and wearing light-coloured clothing.
Detective inspector Phil Jackson, of Leeds District CID, said: “This was clearly a really frightening experience for the victim and we are currently carrying out extensive enquiries to trace the men responsible.
“Bingley Road itself is a fairly out of the way location and these men are likely to have stood out.
“We would like to hear from anyone who thinks they have seen them in the area either before the incident or escaping from the scene.”
Anyone with any information can contact Leeds District CID at Elland Road via 101 or Crimestoppers anonymously on 0800 555 111.