Coronavirus has created a "threefold perfect storm" for abusers, NSPCC Northern Ireland has warned.
The charity is concerned offenders are seeing an unprecedented opportunity to target children who are spending more time on the internet at home.
And many of those may be feeling increasingly lonely or anxious because of the lockdown.
It comes as last week Europol said they seeing "increased online activity by those seeking child abuse material".
Children are passing more time at home than ever before - with much of their day online.
The charity said that while much of this activity will be helping to educate them, stay in touch with their friends and provide entertainment, it could also lead to an increased risk of sexual abuse and exposure to harmful content.
And with social media companies forced to send their outsourced moderators home, meaning they are relying primarily on artificial intelligence (AI) for child safeguarding purposes, the NSPCC is concerned that conditions are "rife" to be exploited by abusers.
The charity is worried that while AI is normally used to identify and triage harmful content, grooming and abuse, there may be less human moderators available to ensure swift action is taken on child abuse and grooming.
Margaret Gallagher, head of local campaigns at NSPCC Northern Ireland, said that the current lockdown and conditions has increased online risk and "brewed a perfect storm for offenders to abuse children".
She explained: "The public health emergency is creating major challenges across society, and like all of us tech firms must adapt. It's vital they set out how they are prioritising protecting children by identifying and disrupting offenders with fewer moderation resources available.
"Social media and gaming sites are proving to be a lifeline for parents and their children as they adapt to being at home, but we must also recognise there are heightened risks.
"It is more important than ever for parents to have regular conversations with their children about what they're doing online and to reassure them they can come to you with any worries."
The NSPCC wants tech firms to share with the Government the volumes of referrals they make during this period to the National Centre for Missing and Exploited Children (NCMEC), in order to track and identify child abuse risks.
And it has also called for the sharing of intelligence with each other about emerging and evolving risks, and how the firms are combating abuse and protecting children in the current emergency.
l The NSPCC's Childline website offers message boards where children can support each other. Alternatively, young people can share their worries with trained Childline counsellors by calling 0800 1111 or visiting the site www.childline.org.uk
Any adults with worries or concerns about a child's welfare can call the NSPCC's Helpline on 0808 800 5000