The crime happened on March 4, between 11am and 2pm, at a house on Halifax Road in Bradford.
Police said the suspects had broken into the home and stolen some World War Two medals and a safe which had cash inside.
The items were placed into a wheelie bin which was then taken to a car which the suspects used to escape.
A statement from West Yorkshire Police said: "Suspects broke the shed in the garden and then into the property and made an untidy search inside. A safe was stolen with cash inside and also some World War Two medals were taken.
"The suspects then fled the scene taking a wheelie bin where they placed the stolen items and got into a car."
Anyone who may have information about the crime, or who may have seen anything suspicious in the area, is asked to call the force on 101, quoting crime reference number 13210110281. Alternatively, contact Crimestoppers on 0800 555 111.