A child reported being approached by a stranger in a car on Heol Y Cae in Pontarddulais last night.
The child described a white car stopping near to where he was playing, before the driver wound down the window and asked him to get in. The child did not respond and ran in to his home nearby to raise the alarm.
The driver is described as between 40 and 60-year-old, with black shoulder length hair which was possibly a wig.
Inspector Emma Fox said: “This is a concerning incident and one we are taking very seriously. However, I would like to remind the public that such incidents are rare and they should remain vigilant but not alarmed.
“Our officers have visited a number of schools in the area to remind staff and pupils about the importance of personal safety and stranger danger, and I would urge parents to reinforce this message at home with their children.
“Enquiries are ongoing and I would appeal to anyone who believes they may have information which could assist the investigation, to come forward.”
Any witnesses or anyone with information should contact 101, quoting occurrence 1800441660.