A 33-year-old resident of Tel Aviv was arrested on Wednesday by the police's Lahav 433 Unit on suspicion of "severe pedophile offenses," police said on Thursday.
The suspect, a computer expert and a veteran of an elite IDF computer unit, allegedly entered children's' Web sites and held sexual conversations with minors.
Police believe the man sexually assaulted a number of girls, and are attempting to track down the alleged victims.
"He offered to meet them, and we suspect he also carried out sexual assault," police said.
The investigation was headed by the Computer Crimes Division of the 433 Unit, under the command of Dep.-Cmdr. Itzik Shofen.
The investigation was launched a week ago, when police received a complaint by a children's' Web site manager who was informed by parents of the suspect's activity.
The parents told the manager that their eight-year-old girl was in touch with a suspicious man. Following Wednesday's arrest, police raided the suspect's home, seizing computers that were allegedly used to communicate with minors.
"Many pictures of minors and pedophilic films that are difficult to watch were seized," police said.
A Petah Tikva Magistrate extended the suspect's custody by a week on Wednesday. The court prohibited publication of the suspect's name and image.