The Nantwich Education Partnership, made up of 15 primary schools and one secondary academy, issued a letter after children reported playing or watching the adult-themed games.
The heads said the games could increase “early sexualised behaviours” and the advice was in line with local authority policy and concerns.
The letter, sent last month, said: “Several children have reported playing or watching adults play games which are inappropriate for their age and they have described the levels of violence and sexual content they have witnessed: Call Of Duty, Grand Theft Auto, Dogs Of War and other similar games are all inappropriate for children and they should not have access to them.
“If your child is allowed to have inappropriate access to any game or associated product that is designated 18-plus we are advised to contact the police and children’s social care as it is neglectful.”
Grand Theft Auto is an action-adventure series of games set in fictional neighbourhoods modelled on American cities, which has become well known for its adult nature and violent themes. Call of Duty is a “first-person shooter” first released in 2003.
Parents were also warned about allowing their youngsters to have accounts on social media sites such as Facebook and WhatsApp because it could make them vulnerable to sexual grooming.
The letter went on: “Access to these games or to some social media sites such as those above increases early sexualised behaviours (sometimes harmful) in children and leaves them vulnerable to grooming for sexual exploitation or extreme violence.”