It is alleged that two men in a white van pulled up on Long Lane and called the children over.
When the girls did not approach the van, one man is said to have chased them on foot.
Notts Police confirmed an incident had been reported to them at around 8pm last night.
They are now appealing for anyone with information about the van or its driver to contact the police.
It is described as a white pick-up truck with a red tail gate and a year 2000 registration plate.
Call Notts Police on 101 or Crimestoppers anonymously on 0800 555 111.