Popular social networking website MySpace has said it is to begin sending online alerts to American users to help find missing children.

As part of an extension of its safeguards for users, MySpace will send online alerts out to users in US regions where a child has gone missing.

In a deal with the National Center for Missing and Exploited Children , MySpace will send out so called Amber alerts, or early warning bulletins in serious child abduction cases.

The Amber alerts - named after nine-year-old Amber Hagerman, who was kidnapped and murdered in Texas in 1996 - will appear in a small text box at the top of a person's profile, MySpace said. Clicking on the alert box will reveal more information about the case, such as photos and information about suspects.

"We've been working with partners and law enforcement to find any possible avenue we can take to protect our nation's children, keeping sex offenders off our site and providing technology that the entire industry can take advantage of," MySpace chief security officer Hemanshu Nigam said in a statement.

MySpace has been criticised of being slow to keep its many teenage users safe from adult predators using the site. Last week, the families of five teenagers sued MySpace for negligence in protecting its users after the youngsters had fallen victim to sexual abuse by adult MySpace users.

MySpace has some 150 million registered users. More than half of US teenagers with internet access use social networking websites such as MySpace, a recent Pew Internet survey found.