MONTREAL – Police in Quebec say they have arrested 13 people who allegedly exchanged advice on ways to sexually abuse children without raising suspicion.

The investigation by Quebec provincial police and the RCMP began three years ago.

About 150 officers from different forces took part in raids Wednesday throughout Quebec and in Toronto.

Those arrested are aged between 27 and 74.

“The probe began in April 2013 after we received tips from the public,” said provincial police Sgt. Christine Coulombe.

“In a nutshell their strategy was to go on online discussion forums to exchange information about their sexual experiences with children. They also discussed what tactics to use and what places to frequent with the aim of sexually abusing children without raising suspicion.”

It was not immediately known how many people were arrested in Toronto.

A Toronto police spokeswoman referred a call for information to Quebec authorities.

Police also seized computer material.

The accused are expected to be arraigned in Montreal on Thursday.