The arrests of almost 200 people on suspicion of child sex crimes, from grooming to live streaming abuse, have stoked fears about the growing online exploitation and trafficking of children in Britain, anti-slavery groups said on Wednesday.

A third of 192 arrests made in a recent week-long crackdown were for severe offenses, such as blackmail and live streaming, according to the police and the National Crime Agency (NCA) — dubbed Britain's FBI — while 245 children were saved from harm.

"We know that as children's online habits change, offenders are adapting with them," said Zoe Hilton of the NCA.