The number of young people seeking help after seeing online pornography is rising sharply, according to a leading children's charity in the UK.

Childline's British branch reported a 60% increase in counselling sessions with children left worried about what they had seen on the internet.

Just over half of those contacting the service last year were aged between 12 and 15. 

Earlier this year, the Irish Society for the Prevention of Cruelty to Children (ISPCC) warned that children as young as six are viewing pornography. 

Others are using sexualised language and engaging in sexual activity at a young age, including texting or sharing nude images of themselves, according to its annual report.

Cliodhna O'Neill of the ISPCC called it "a growing and ongoing problem".

"We have seen a definite increase in children being exposed to pornography online and within the home, sometimes with parental knowledge, in the last five years," she said.

The new Childline figures are released as a growing movement in Australia works to discourage the consumption of porn.

Toowoomba, in southern Queensland, is striving to become "a city free from porn", with a local church group City Women leading the charge. The mayor has put his support behind the movement.

Speaking at a recent rally, he asked the town’s citizens to "acknowledge that viewing pornography promotes exploitation of women and violence against women and damages families".