Ontario Provincial Police say they have laid charges against 80 people after a provincewide investigation into internet child exploitation.

The charges involve more than 274 offences, including sexual assault, and making, distributing and accessing child pornography, police said Thursday.

Charges involve more than 274 offences, including sexual assault, making, distributing and accessing child pornography 4:10

A total of 174 search warrants were carried out in recent days.

Additional arrests are pending.

One of the 80 who were charged is underage so cannot be named under the Youth Criminal Justice Act.

Police said 20 victims were identified during the investigation.

Investigators found minors, including girls aged 14, 15 and 16, working in the sex trade against their will and police rescued them, removing them from the situations that they were in and taking them to safety.

OPP Chief Supt. Don Bell told reporters at a hotel near Toronto's Pearson airport on Thursday that the charges are a result of 27 police forces working together, including the RCMP, Canada Border Services Agency and U.S. Homeland Security.

"Child pornography is sexual abuse of our children and every image of child pornography is a revictimization of that child," Bell said.

"The creation and distribution of images of child sexual abuse, the luring of young people by predators and the proliferation of internet sites where pictures of every imaginable sex act can be accessed by anyone, continues to be a major concern to police agencies worldwide."

Sgt. Peter Leon, spokesman for the OPP, said Homeland Security was at the news conference in a supportive role.

"There are borders between Canada and the U.S., but electronic crimes know no borders. It shows that there is a working relationship between law enforcement agencies on both sides of the border and we are working together to combat these crimes," he said.

Video shows IP addresses

Police displayed a video that showed 2,038 unique IP addresses in Ontario that indicated the user was either a "download candidate" for suspected child pornography, or that the user was present on a known child exploitation website. These IP addresses were observed over the past 90 days.

Inspector Lisa Taylor, manager of the OPP electronic crime section, said the charges announced today are a reminder of the dangers of the internet for children.

"Children, teens and parents have a responsibility to educate themselves to ensure their online experiences are as rewarding as they want it to be and as safe as it needs to be," Taylor said.

One of the 80 people charged is a 37-year-old Brampton, Ont., man who was released on bail on Monday after he was charged with possessing and accessing child pornography.

The man is an employee of the Milton Community Resource Centre, a daycare. He is due back in court on May 16.

Rebecca Barrows-Vrankulj, executive director of the Milton daycare, said in a statement on Wednesday that the man is no longer on the premises and a letter has been sent home to parents.

"News of the investigation is deeply troubling to us and members of our greater community. The centre assures everyone, especially parents, that we are cooperating with police to assist them in their investigation," she said.

The letter to parents said that "the staff person in question has been removed from the premises and will not be returning throughout the duration of the investigation."

The Provincial Strategy to Protect Children from Sexual Abuse and Exploitation on the Internet, a co-ordinated approach to internet crimes developed by police services that began in August 2006, has completed 32,808 investigations and laid 11,408 charges against 3,310 people.

During that time, 870 child victims have been identified in Ontario. Another 173 child victims were identified internationally.