Police are appealing for information after two women were sexually assaulted while in their beds through their windows.
Police said the separate incidents, involving a woman and a teenage girl, occurred within a few hundred yards of each other at addresses just off Aldwick Road in Bognor Regis.
In each case the victims were touched over their clothing by someone reaching in through open windows.
One incident occurred on April 30 at around 5am, the other on May 14 between 6am and 7am.
Detective Inspector Alan Pack said: ‘We are keen to hear from anyone who may have information about either incident, perhaps having noticed suspicious activity in the early hours at these locations.
‘It left those assaulted feeling both shocked and traumatised.
‘Given the similarity of the circumstances and the proximity of these two incidents, we have not ruled out the possibility that they may be linked.
‘Enquiries are continuing and we would urge anyone else who may have been assaulted to come forward.
‘Meanwhile police patrols in the area have been increased.’
Police are encouraging people to consider their night-time security, particularly people who sleep with windows ajar at ground level.
DI Pack said it was advisable not to leave externally accessible windows open at night, and fit locking devices could prevent them from being opened more than an inch or two to permit ventilation.
Anyone with information that may assist detectives is asked to report it online at www.sussex.police.uk/contact-us/response-to-appeal/.
Alternatively reports can be made via email email@example.com or by calling 101, quoting serial 1481 of 14/05 (for the incident on May 14) or 487 of 30/04 (April 30).
Anonymous contact can be made via independent charity Crimestoppers anonymously on 0800 555 111 (www.crimestoppers-uk.org).