Facebook has agreed to change the way it handles complaints in an attempt to protect children from sexual predators and inappropriate content.

The social networking site, which has than 47 million members, will bring in a fast-track process for dealing with complaints about nudity, pornography and unwelcome approaches. Prospective members will also be warned about the risks of social networks before they sign up.

The agreement came after an investigation by Andrew Cuomo, the New York attorney general, who had received complaints about inappropriate content on the website.

“Social networking sites, popular among young people, have quickly gained members and appeal, but also act as a magnet for those who would prey on the young,” Mr Cuomo said.

Websites such as Facebook and MySpace have been criticised by child safety campaigners, who say that they give paedophiles anonymous access to large numbers of children.

In July, MySpace said that it had removed 29,000 American sex offenders from its network after pressure from US state governments. British police said at the time that they had no plans to give MySpace names of sex offenders so that they too could be evicted from the site.

During Mr Cuomo’s investigation into Facebook, his office set up accounts and sent complaints to moderators to test the site’s procedures. Chris Kelly, Facebook’s chief privacy officer, acknowledged that the checks had revealed problems.

“The attorney general pointed out some weaknesses in our complaint-handling process,” Mr Kelly said. “What he has directed us to do is renew our vigilance around complaint handling.”

Under the new procedures, complaints about pornography and harassment will be given priority over the tens of thousands of complaints received by the site every day. Facebook will have to respond to such complaints within 24 hours and reply to the complainant reporting what steps it has taken within 72 hours.

An independent examiner will monitor the effectiveness of the process.

Mr Cuomo said that efforts were continuing to develop a comprehensive age verification system that could be used by all social networking sites.