Two young males were seen entering the bin store area outside a property in Marett Court in Marett Road between 5.30 and 5.50 pm.
The subsequent fire was attended by two fire engines and the St Helier road had to be closed while firefighters in breathing apparatus worked to extinguish the flames.
Anyone with any information is asked to contact the police on 612612 or Crimestoppers on 0800 555 111.
