MORE than half of children have used an online social network by the age of 10, according to a study.

Facebook tops the list of sites that children sign up to under-age, with 52% of eight to 16-year-olds admitting they had ignored the official age limit, the Social Age report for online safety advisory website Knowthenet found.

Other popular sites include WhatsApp, used by 40% of eight to 16-year-olds, BBM (24%), SnapChat (11%) and Ask.fm (8%).

The study found that although 59% of children are social networking by 10 years old, just 32% of parents feel "very confident" about helping them stay safe online.

The poll found 21% of children had posted negative comments, starting from an average age of 11.

Dr Richard Woolfson, child psychologist and Knowthenet spokesman, said: "Parents can no longer protect children by simply trying to limit their online experiences. Instead parents need encourage children to share both good and bad online experiences, talk openly about the risks they may encounter online without scaring them and make sure they keep up with the latest social media crazes."