Four men have been jailed in Bahrain for convincing young British boys to send sexual images of themselves, it has been reported.
They were convicted of offences that included the sexual assault of children and forcing children by threats and blackmail to perform obscene acts, according to the BBC.
One of the victims was contacted via Blackberry Messenger and following conversations online was encouraged to perform sexual acts via a webcam.
The offenders - aged between 19 and 21 at the time - pretended to be girls and sent indecent images of what they said was themselves, then requested others in return.
The men then threatened to post the victims' images on internet sites or send them to friends and family unless more images were sent.
The National Crime Agency's Child Exploitation and Online Protection (CEOP) command began investigating in January 2012 after a boy told police he had been contacted by a person claiming to be a 13-year-old girl from Rome.
The offenders were traced to Bahrain, while police identified 37 victims in the UK.
A total of 249 children were confirmed to have been targeted but there were suggestions the offenders had sought to abuse "many others in the UK and around the world", the BBC said.
CEOP deputy director Andy Baker said the online sexual abuse had been "harrowing". The offenders had targeted children across multiple time zones to ensure there were always possible victims.
"These offenders used the 'scatter gun' approach to target as many victims as possible, playing the averages in their pursuit of victims," he was quoted as saying.