The incident took place on 20 November between 22:00 and 23:00.
“Officers would like to speak to anyone who may have witnessed this incident, have information regarding this case, or who saw anyone acting suspicious in the area at the time,” said Guernsey Police.
“If you have any information regarding this incident, you are asked to contact DC 92 SMITH on 222 222 or to contact Crimestoppers anonymously on 0800 555 111 quoting reference 2300008827.”