Police are investigation after blood and broken windows were found at Guernsey's King Edward VII Hospital.
Someone damaged the former hospital in Castel sometime overnight on Friday 6 September by throwing stones through the windows.
Police believe someone was injured, due to the blood left at the scene.
Anyone with more information is asked to contact PC 25 Graves on 222 222 or Crimestoppers anonymously on 0800 555 111.