More than 40 police forces have been involved in raids as part of an operation targeting suspected internet paedophiles.
Several people have been arrested in the raids which have taken place over the last 48 hours in the operation led by the Child Exploitation and Online Protection Centre (Ceop).
A spokeswoman for Ceop said there have been two days of "operational activity" involving more than 40 forces across the UK.
"There have been a number of warrants that have been executed and a number of arrests that have been made," she said.
Ceop is today publishing a report on the risk posed by people who possess indecent images of children and recommendations about how police can protect children.