Police are reminding young people to be absolutely sure that they know who they are making friends with on social media.
Cheshire Police has received a number of reports of Facebook profiles, being created by individuals pretending to be a young person and befriending children online.
PC Helen Harrison, of Sandbach Neighbourhood Policing Team, said: "What they are doing is firstly establishing a "friendship" or connection with a young person through Facebook and then sending them sexually explicit images through the messenger services.
"It is children who are seeing images and we are urging parents and carers to pay close attention to their child's use of social media and provide them with advice and guidance to ensure they remain safe online.
"Sharing our personal lives with friends and loved ones on social media can be fun and rewarding. However, if we don't pay attention to the security of our social media profiles, it allows strangers to also have the exact same access.
"This is a criminal offence and any such reported incidents will be fully investigated."
If you or anyone you know has been a victim of inappropriate messages received online please contact Cheshire Police on 101. Information can also be passed on anonymously via Crimestoppers by calling 0800 555 111.
Cheshire Police is issuing the advice and guidance below to help stay safe online
Never accept a friend request from somebody you have never met or do not know in person
Check the security settings on all social media profiles and ensure they are set at the maximum level
Parents and carers to sit down with children and young people and look through their friends list, deleting anyone who is not known to them or their child
It is recommended children under the age of 13 do not use Facebook or similar social media
More advice on online protection for children and young people can be found at:
CEOP (Child Exploitation and Online Protection Centre)