The Messenger of Allah[peace be upon him] has mentioned, "When the night approaches then prevent your children (from venturing outdoors) because verily Shaitaan spreads out at this time, ....." (Hadith-Sahih Bukhari).
In another narration Rasulullah[pbuh] has stated,
" Don't let your animals and children out from the time the sun sets until the first portion of darkness passes (i.e. Esha time sets in), for indeed Shaitaan sets out from the time the sun sets until the first portion of darkness passes by." (Hadith-Sahih Muslim)
Safeguarding our children from the evil elements that lurk in our environment is an incumbent duty of the parents, just as it is incumbent to safeguard them from all other evils.
The tendency today is to allow children the freedom to roam out of the house during this time, when the Shayateen and their evil influences are at their strongest.
From the above narrations we learn that parents are duty-bound to ensure that children are given the necessary protection during this time in an Islamic environment.
May Allah Ta'ala protect our innocent children from all forms of evil. Aameen