A total of 39 charges have been laid and 10 men arrested, including four from northern Ontario, in a online child luring and sexual exploitation investigation dubbed Project Limestone, police say. One of the men arrested is a repeat offender who was out on bail. "It only took 1.5 hours for an adult to begin speaking to an undercover investigator posing as a child online and arriving at a location to meet them. Others arrived at a pre-set location with candy, toys and sexual paraphernalia," Ontario Provincial Police said in a social media post Thursday. "This all occurred during a four-day period." Project Limestone was a collaborative effort between OPP and municipal police agencies in Greater Sudbury, North Bay, Sault ste. Marie, Durham, York and Peel that took place between Sept. 12 and 15. "Investigators utilized undercover techniques to access online chatrooms and social media applications designed for children in order to identify, locate and arrest persons looking to sexually exploit children," OPP said. Two of the suspects arranged to meet undercover investigators who were posing online as mothers with young children. "Six individuals were arrested when they showed up to a pre-set location to meet with the investigators posing as children online," police said. A total of 55 devices were seized between the 10 suspects. "The amount of people that are looking to meet with children in real life for sexual purpose is definitely disturbing," OPP Det. Staff Sgt. Tim Brown said in an interview with CTV News. Here is a list of the suspects, their charges and court status: "With the increase in technology and social media and what not, it increases the chances of individuals who like to prey on children," said Ins. Scott McFarlane of North Bay Police Service in an interview. "The North Bay Police Service has been part of a provincial joint forces team, called the provincial strategy, for some time."