Young Facebook users will be able to report suspicious or inappropriate online behaviour with the launch of a new safety application.
The panic button has been installed following the murder of Ashleigh Hall
Children can use the facility to report abuse to the Child Exploitation and Online Protection Centre (Ceop) and Facebook.
An advert to download the ClickCEOP application will automatically appear on the homepage of every user aged between 13 and 18.
The launch follows months of negotiation between Facebook and Ceop, the Government law enforcement agency tasked with tracking down online sex offenders.
Ceop called for the "panic button" application to be installed in November but Facebook has resisted the idea.
Bebo became the first network to add the button, followed by MySpace while Facebook maintained that its own reporting systems were adequate.
However, pressure mounted on Facebook following the rape and murder of Ashleigh Hall, 17.
Ashleigh was killed by a 33-year-old convicted sex offender, posing as a teenage boy, whom she met on Facebook.
Forty-four police chiefs in England, Wales and Scotland, signed a letter backing Ceop's call for a panic button on every Facebook page.
Users will be able to bookmark the ClickCEOP service or add it as an application to find information about online safety.
Jim Gamble, chief executive of the Ceop centre said: "Our dialogue with Facebook about adopting the ClickCEOP button is well documented - today however is a good day for child protection.
"We know from speaking to offenders that a visible deterrent could protect young people online."
Facebook's Joanna Shields added: "There is no single silver bullet to making the internet safer but by joining forces with Ceop we have developed a comprehensive solution which marries our expertise in technology with Ceop's expertise in online safety."
James Brokenshire, minister for crime prevention said: "It's a sad fact that we are now seeing more cases where sex offenders are using social networking sites to conceal their identities in order to contact children."
The panic button has been installed following the murder of Ashleigh Hall
Children can use the facility to report abuse to the Child Exploitation and Online Protection Centre (Ceop) and Facebook.
An advert to download the ClickCEOP application will automatically appear on the homepage of every user aged between 13 and 18.
The launch follows months of negotiation between Facebook and Ceop, the Government law enforcement agency tasked with tracking down online sex offenders.
Ceop called for the "panic button" application to be installed in November but Facebook has resisted the idea.
Bebo became the first network to add the button, followed by MySpace while Facebook maintained that its own reporting systems were adequate.
However, pressure mounted on Facebook following the rape and murder of Ashleigh Hall, 17.
Ashleigh was killed by a 33-year-old convicted sex offender, posing as a teenage boy, whom she met on Facebook.
Forty-four police chiefs in England, Wales and Scotland, signed a letter backing Ceop's call for a panic button on every Facebook page.
Users will be able to bookmark the ClickCEOP service or add it as an application to find information about online safety.
Jim Gamble, chief executive of the Ceop centre said: "Our dialogue with Facebook about adopting the ClickCEOP button is well documented - today however is a good day for child protection.
"We know from speaking to offenders that a visible deterrent could protect young people online."
Facebook's Joanna Shields added: "There is no single silver bullet to making the internet safer but by joining forces with Ceop we have developed a comprehensive solution which marries our expertise in technology with Ceop's expertise in online safety."
James Brokenshire, minister for crime prevention said: "It's a sad fact that we are now seeing more cases where sex offenders are using social networking sites to conceal their identities in order to contact children."