The incidents happened in the Waring Drive area of the town at around 12.20am on Saturday, May 11.
Officers on Monday (June 24) released CCTV footage of a person they wanted to identify.
A spokesman for Lancashire Police said: “We would like to speak to the person in the footage in connection with our investigation.
“We know that this footage isn’t of the highest quality, but if you recognise them, please contact us on 101 quoting log 0552 of May 11.”
Information can also be reported online at https://doitonline.lancashire.police.uk/.
Alternatively, independent charity Crimestoppers can be contacted anonymously on 0800 555 111.
