Detective Constable John Goddard said it was a lucky escape.
The girl had been medically assessed and was now recovering at home, he said.
"The young female was extremely vulnerable and was targeted by a group of teenagers and was very lucky to escape without serious injury," he said.
"We are appealing for the public's help in identifying anyone that may be able to assist us."
Police are looking to talk to anyone who may have seen the group of teens or the young girl that night.
She was wearing a black puffer jacket, black leggings and a grey and white top.
Anyone with information about the attack or the offenders are asked to contact Mr Goddard on (07) 855 0151 or anonymously via Crimestoppers on 0800 555 111.