South Yorkshire Police records show that there were 238 offences of taking or distributing indecent photographs of children, where suspects were under 16 years old, between September 1, 2015 and August 31, 2016.
The incidents were all recorded as crimes.
Some police officers have been visiting South Yorkshire schools to warn children of the dangers of sending explicit photographs of themselves to others and of recipients forwarding them on to others.
NSPCC North of England Campaigns Manager, Helen Westerman, said: “Last year, Childline held 1,392 counselling sessions with children worried about sexting or sharing sexually explicit images, with more than half of these aged between 12 and 15 years old.
“Some children will send sexually explicit images and messages because they feel pressured into doing so, while others will do it for attention or to feel a little more grown up.
“The reasons can be complicated and varied, but with so many children having access to mobile technology and communication at the touch of a button, it’s easier for these images to be sent and shared than ever before.
“It is important children are made aware of the consequences – not only the legal ones, but also the fact that when something is shared it’s very difficult to control. You don’t know who is going to see it once it’s sent, and it’s very difficult to get the image taken down.
“It’s also vital parents talk to their children about what they’re doing online and find out what they’re sharing and accessing, and who they’re talking to.
“For parents who may need a little help in understanding more about their children’s online activities, we have a programme called Share Aware and run workshops for parents.You can find out more information about this on the NSPCC website.
“Childline is also there to help children and young people if they are worried about sexting, offering counselling online at www.childline.org.uk and on 0800 11 11. The website also has information about what to do if an explicit image has already been shared, and help to get that image taken down.”