Officers are appealing for information and witnesses after a woman was assaulted in Hatfield Garden Village.
The incident occurred on a grass verge outside Arla warehouse on Monday night (3 July), sometime between 9.30pm and midnight.
The victim was pushed to the ground and grabbed by a man known to her before another woman intervened to check that she was ok.
Detective Constable Jasbir Pawar said: “We are appealing for any witnesses or anyone with information to come forward and we are particularly keen to hear from the lady who intervened. If this was you, please get in touch.
“The victim and the suspect had been walking in the area between around 9.30pm and midnight, covering Lavender Close, Poppy Walk, Manor Parade shops, Gypsy Moth Avenue and Campion Road. If you think you saw them during this time and have information that might help, I would also like to hear from you.