Police are appealing after two girls, aged ten and 16, were reportedly approached and followed by an unknown man in Ystrad Mynach.
The incident is said to have happened on Commercial Street at around 8.30am on Wednesday, November 6.
The man reportedly tried to engage the girls in conversation before following them for “a short distance”.
Gwent Police are carrying out enquiries.
Sergeant Emma Sowrey, of Gwent Police’s Caerphilly North local neighbourhood policing team, said: “While this incident was distressing for the children involved, they were not harmed in any way.
“If you any information please call 101 quoting ref 1900410294 or you can send a direct message to our Facebook or Twitter social media pages.
“You can also contact Crimestoppers anonymously by calling 0800 555111.”