Police have begun investigating a report of a man sexually assaulting a woman in Bewbush Drive, Crawley around 8.15pm on Saturday (27 March).
According to officers, a male unknown to the the victim grabbed her.
She was then able to run to a place a safety.
On Sunday, enquiries were continuing to try to identify the suspect, as officers confirmed their intention to conduct additional patrols in the local area.
Chief Inspector Shane Baker said on Sunday afternoon:
"Our teams will be carrying out immediate actions including house to house enquiries as we work to identify the suspect responsible.
"We are treating this an isolated incident.
"However we will be carrying out additional patrols to provide reassurance to the local community."
Anyone who witnessed what happened or who has information that may assist with enquiries is urged to report online or by calling 101, quoting 1495 of 27/03.