Detectives are hunting a man who has been acting suspiciously at fast food outlets across Perth while seated near young children.

Police fear the man may be recording children and may have also indecently exposed himself to them.

The man attended fast food outlets in Warnbro, O'Connor, East Perth, Halls Head, Cannington and Ellenbrook. Credit:WA Police

In the past month the man has gone to several fast food outlets during the day and sat near young children.

Police say he has been placing a cardboard box on the table and it is possible there was a recording device inside.