An 18-year-old Ottawa teen has been charged with forcing young girls to commit sex acts online.

Police allege that Ryan Earl McCann recruited girls to perform in front of their web cams using extortion and threats.

He then allegedly posted the images online.

Some of the girls were as young as 14.

Police say they identified 18 alleged victims in Ottawa and the Durham Region of southern Ontario.

They believe there could be more victims.

McCann faces a number of charges including sexual assault, extortion, fraud and distributing child pornography.

He'll appear in court on Tuesday.