A campaign to encourage children who are being physically abused to seek help is being launched today as new figures show a link between abuse and self-harm and playing truant from school.

ChildLine Scotland has made a short film starring the child actor Sammy Williams as a boy who is being physically abused by his father. The film shows the boy being beaten up by his dad when he gets drunk.

"When my dad drinks," he says, "I honestly don't know what he might do.Maybe I make things worse."

Childline Scotland hopes the film, which is being launched online, will encourage more children to call the charity's 24-hour helpline.

The film is being released along with a survey showing half of 1300 young people who had suffered abuse said it had caused them to harm themselves and more than one-quarter said it had led to them staying away from school.

In 2011/12, one in 10 calls to the helpline was about physical abuse and the perpetrator was just as likely to be the child's mother (32%) as the father (31%). A further one in 10 reported both parents had physically abused them.

Most of the young people contacting ChildLine about physical abuse were aged between 12 and 15 although 24% were under the age of 11 and a few were as young as five.