Pope Francis on Friday denounced the proliferation of adult and child pornography on the internet and demanded better protections for children online - even as the Vatican confronts its own cross-border child porn investigation involving a top papal envoy.

Francis met with participants of a Catholic Church-backed international conference on fighting child pornography and protecting children in the digital age. He fully backed their proposals to toughen sanctions against those who abuse and exploit children online and improve technological filters to prevent young people from accessing porn online.

Francis said the Catholic Church knew well the 'grave error' of trying to conceal the problem of sexual abuse - a reference to the church's long history of cover-up of priests who have raped and molested children around the world.

Pope Francis denounced 'extreme pornography' on the web that adults consume and the increasing use of 'sexting' and 'sextortion' among the estimated 800 million minors who navigate the internet

He said an international, cross-disciplinary approach was needed to protect children from the dark net and the 'corruption of their minds and violence against their bodies.'

Using terms that are certainly new to papal lexicon, Francis denounced 'extreme pornography' on the web that adults consume and the increasing use of 'sexting' and 'sextortion' among the estimated 800 million minors who navigate the internet.

'We would be seriously deluding ourselves were we to think that a society where an abnormal consumption of internet sex is rampant among adults could be capable of effectively protecting minors,' he said.

The conference was planned some two years ago, but it unfolded precisely at the time when the Vatican was confronted with a kiddie porn scandal of its own. The Vatican recalled from its embassy in Washington one of its senior diplomats who has been caught up in an international child porn investigation. Canadian police have issued an arrest warrant for Monsignor Carlo Capella, accusing him of accessing, possessing and distributing child pornography during a visit to an Ontario church over Christmas. He is now in the Vatican, where prosecutors have opened an investigation.

The Vatican in 2013 criminalized child porn possession, distribution and production, with sanctions varying from up to two years and a 10,000-euro fine ($11,170) to 12 years and a 250,000-euro fine.

Some U.S. church officials and critics balked at the recall, saying the Vatican should have waived diplomatic immunity and allowed Capella to face charges in the U.S. or Canada. Vatican officials have defended the recall as consistent with common diplomatic practice and suggested that Capella will face a criminal trial in the Vatican if the evidence warrants it.

Participants at the congress offered sobering statistics about the problem: Last year, Interpol identified five child victims of online abuse every day, while the Internet Watch Foundation identified more than 57,000 websites containing child sexual abuse images.

The pope met with participants of a Catholic Church-backed international conference on fighting child pornography and protecting children in the digital age

The conference, which drew leading researchers in public health, Interpol, the U.N., government representatives as well as executives from Facebook and Microsoft, issued a 13-point call to action that it presented to Francis on Friday.

Their declaration demands that:

Lawmakers and governments improve laws to protect children online and punish perpetrators of child porn production

Technology companies develop better ways to block redistribution of porn and attack the proliferation of child porn images already on the web

Law enforcement agencies improve information sharing and ensure help for young victims of online exploitation

Health professionals enhance training to recognize signs of abuse and increase research into the effects of viewing porn on young minds

Faith leaders, governments and civil society to increase awareness about the problem.

Francis said he wanted each of them to remember that children look to adults, with light in their eyes and trust in their heart, to protect them.

'What are we doing to make sure they are not robbed of this light, to ensure that those eyes will not be darkened and corrupted by what they will find on the internet?'