SPRINGFIELD, Mass. -- A Canadian man has been sentenced to 15 years in prison for enticing two preteen girls from Massachusetts into sending send him sexually explicit photos of themselves.

Federal prosecutors say 35-year-old Justin Carl Wong, of Alvinston, Ontario, was also sentenced last week to 10 years of probation.

He pleaded guilty in July to 10 counts of sexual exploitation of a minor.

Wong met the girls in 2012 on a messaging app. They were 10 and 8 at the time and lived in Hampshire County. Authorities did not provide a town.

Prosecutors say he used psychological pressure and insults to bully the older girl into sending him sexually explicit pictures. She also sent some of her with the younger girl, and then he pressured the younger girl to send more.