Experts are preparing for a spike in public reports of child sexual abuse on the internet as schools across the UK close during the coronavirus pandemic.
The Internet Watch Foundation (IWF) is concerned children might be at greater risk of being groomed and coerced into making explicit content, given that many will undoubtedly spend more time online from Monday.
Susie Hargreaves, the charity's chief executive, said videos and photos are increasingly taken by the children themselves, who have been targeted by "ruthless predators" under false identities.
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"Heartbreakingly, we see more and more of this material being filmed by children themselves on devices, sometimes livestreamed from their own bedrooms in the family home," she said.
"My fear is that, with more young children being sent home from school, more of them will be spending a lot longer online, possibly exposing them to some of these criminals."
In 2019, the charity – which is responsible for finding and removing videos and images of children suffering sexual abuse from the internet – looked into a record of 260,400 reports, up from the 229,328 it investigated the year before.
Of those in 2019, 132,700 were confirmed to be of images or videos of children being sexually abused, an increase on the 105,047 in 2018.
The charity says its hotline will continue to operate while other staff members are forced to work from home to prevent the spread of Covid-19.
"We are bracing ourselves for a spike in reports," Ms Hargreaves said.
"The pandemic is forcing more and more people to stay indoors, and a lot of people are going to be spending much more time on the internet and at home on electronic devices.
"More people alone in their homes and more people spending longer online sadly means we are likely to see more people stumbling across criminal material involving child sexual abuse on the internet.
"We are also expecting criminals to be more active on the internet during the coming months.
"This could mean we'll see an unprecedented number of public reports to our hotline as more people spot things that are not right and report it to us."
The charity urges parents to trust their children but to have a frank conversation with them about the dangers.
It has also been reported that teachers believe children could be targeted by county lines gangs as schools shut down.
The Children's Society charity told The Independent: “School provides a safe place and supervision for vulnerable children, and it is a real concern that without this they may be more at risk of being targeted by criminals seeking to exploit them.
"Some children may be living in difficult situations at home and without social interaction and support during the day at school, they may be more likely to go missing, which we know can increase the risks of exploitation.
"Families living in poverty are also likely to face further financial challenges in the coming months, which criminals may try to exploit by grooming children with promises of easy cash.
"While it is welcome that the government has said all vulnerable children should be able to attend school, we know that many are hidden from view and may not benefit from a social care status that means they can continue to do so."