I had this happen on my allotment. Gun site on Grange Lane, but two years ago. A bunch of kids hahging around, so I thought I would be friendly instead of being anti young people. They distracted me, took my bag and raided my car, which I left unlocked. I knew where they went to school as they told me!. So reported it there. If your plot is on Grange Lane like mine, take care at lunch times