Nearly 60 people have been arrested in what Canadian police said on Thursday was the country's largest investigation into child pornography on the Internet.

Arrests or searches were made in all 10 Canadian provinces and three territories. The charges including sexual assault, and possession and production of child pornography, the Royal Canadian Mounted Police said.

Fifty-seven people have been arrested so far, and more charges are expected to be filed in coming weeks, according to police, who said they have also seized about 130 computers believed to contain pornographic material.