Children as young as ten are getting hooked on a ‘pick and mix of horror’ online which is placing them on a ‘conveyor belt’ to terrorism, a top officer warned yesterday.

Vicki Evans, senior national co-ordinator for counter terrorism policing, said officers were seeing a ‘rapidly increasing fascination with extreme violence’ among schoolchildren who are searching out horrific violence, ‘gore’, extreme pornography, and racism online.

The Metropolitan Police Deputy Assistant Commissioner warned youngsters were being drawn to terrorism after watching ‘grotesque’ videos of school massacres and were ending up ‘shopping, picking between (terrorist) ideologies’, with officers finding ‘staggering’ internet search histories for ones so young.

Speaking for the first time since taking up the role earlier this year, Ms Evans said: ‘What is new and becoming far more common and more prevalent is this rapidly increasing fascination with extreme violence and extreme content that we’re seeing throughout our case work.

‘The type of material that we’re encountering, and my officers and staff are encountering in casework, is absolutely staggering and horrific.

‘So we are seeing search histories which contain violence, misogyny, gore, extreme pornography, racism, fascination with mass violence, school massacres, incel.

‘Sometimes that’s coupled with terrorist material, sometimes it’s not. But what it absolutely is a pick and mix of horror.

‘I can genuinely say I wouldn’t wish the search histories that we see in some of our cases on anyone. 

‘These sort of grotesque fascinations with violence and harmful views that we’re seeing are increasingly common.’

She added: ‘We most definitely need to think differently about how we stop that conveyor belt of young people who are seeing and being exposed to this type of material, and unfortunately, sometimes then going on to commit horrific acts.’

Police arrested a record number of children, some as young as 12, for terrorism offences last year.

Children aged 11-15 now make up the largest proportion of referrals to the Government’s de-radicalisation Prevent programme.

Of the 6,884 referrals made to Prevent in the year to March, 40 per cent (2,729 referrals) were aged 11-15, and hundreds of youngsters under the age of 10 were also referred.

Overall, police and security services have stopped 43 late-stage terror plots since 2017, including two Islamist and one extreme right-wing plot in the last 12 months which would have resulted in mass casualties.

Some were ‘goal line saves’, Ms Evans said.

She described the terror threat as ‘smouldering’, adding: ‘We have some really deep, dark hot spots, some pockets where we cannot leave the activity and the groups unattended, and we need to continue to maintain our focus on them to keep the threat at bay.’

One of the major concerns is that recent turmoil in Syria could ‘create a space for extremism and acts of terror’ in the UK.

Ms Evans said: ‘In light of events in Syria, I can absolutely confirm that we’re proactively reviewing our casework, proactively identifying whether there are any new risks in our system that have been inspired or committed by the events.’

She warned that expressing support for HTS, the group that has taken control of the country, would be considered a crime because it has banned as a terrorist organisation in the UK.

Counter terrorism police has seen the caseload linked to hostile state activity rise fivefold in the last few years, she added.