Ontario provincial police say they have rescued two children and arrested 31 people in what they are calling the largest child pornography investigation in the province's history.

Police said Thursday that a 4-year-old boy and a 12-year-old girl were rescued in Wednesday's raids.

The suspects face 93 charges including possession of child pornography and making child pornography. Police say more charges may come.

They say the people arrested include three youths and a 60-year-old man.

Ontario Provincial Police Commissioner Julian Fantino says the arrests are a result of improved tools to track down alleged child pornographers on the Internet.