Nearly 200 suspected paedophiles were arrested in one week, investigators have said, as they warned of a rise in the use of live streaming to sexually abuse children.

The National Crime Agency (NCA) said a UK-wide operation in October had saved 245 children from harm and 192 people were detained.

Nearly a third (30%) of the cases involved the most serious offences including live streaming, blackmail and grooming and 18 of those arrested were said to be in a position of trust, working in areas such as teaching, healthcare and criminal justice.

Police believe dangerous suspects are using live streaming to bombard their targets with comments, using dares, threats or the offer of rewards such as “game points”, to try to manipulate them into nudity on a webcam.

Chief Constable Simon Bailey, lead for child protection at the National Police Chiefs’ Council (NPCC), said: “We need internet companies to help us stop access to sexual abuse images and videos and prevent abuse happening on their platforms. We need parents and carers to talk to their children about healthy relationships and staying safe online.”

The NCA and NPCC launched a campaign on Tuesday to encourage parents to be alert to the dangers of live streaming and warn their children of the risks.

An online survey, answered by 927 people, found 84% said they were alert to the online threats children faced but 58% were unsure if their internet security was strong enough and 30% said they had not spoken to their child about web safety in the last month.

“We know that as children’s online habits change, offenders are adapting with them,” the NCA’s head of safeguarding, Zoe Hilton, said. “These individuals are learning how young people communicate online and are using this knowledge to contact, befriend and abuse them.

“It’s great to see that so many parents are aware of the potential dangers children face online, but with this campaign we’re asking them to make sure they familiarise themselves with their children’s online behaviour and keep that knowledge up to date.”