GENEVA (AP) – The United Nations migration agency is warning that criminal networks have been trafficking hundreds of thousands of people – many of them educated English speakers – to work in online scam centres, and the caseload is growing.

The International Organization for Migration (IOM) says victims are often lured by fake job advertisements – mostly through social media – promising work abroad, only to get locked up, have their identity documents seized, and forced through violence, threats and "debt bondage" to participate in the online scams.

"We're seeing so many more of these cases emerge right now," IOM Director-General Amy Pope told reporters in Geneva on Tuesday. "We're seeing victims from over 80 different countries being trafficked into the scams."