BRUSSELS (AP) — Belgian Prime Minister Alexander De Croo said on Friday that he will seek the help of government experts on extremism in the wake of a series of school arsons. Officials believe the attacks are connected to a controversial sexual education school program.

De Croo spoke just hours after a sixth school in the French-speaking Wallonia region was torched this week. Signs protesting the so-called Evras program were discovered in some of the schools, according to authorities.

The program is a required four hours of training for students aged 11 to 12 and 15 to 16, intended to help them develop their relational and sexual lives. The program had been around and available for all age groups for years, but was not compulsory until now.

“In a democracy like ours, we will never allow our schools to be a target,” De Croo said. “We live in a country of tolerance, and tolerance means we can have a debate, different points of view, but it can never lead to violence, especially in places frequented by our children.”

Interior Minister Annelies Verlinden on Friday called for a halt to the attacks.

“We don’t touch our schools,” Verlinden said during a news conference with De Croo. “It’s a red line.”

De Croo said he has asked the body in charge of processing intelligence on “terror, extremism and radicalization” to analyze the situation, and Verlinden said she's asked the federal police to provide support to local forces in the affected region.

No one has claimed responsibility for the fires set to the six schools, and no suspect have been arrested. This year, around 100,000 students in the Wallonia-Brussels federation are required to attend the two sessions for a total of four hours of training.

Protests, with a few hundred people taking part, have also been organized in Brussels.

Several Islamic groups have also condemned the program in a joint statement, fearing it will favor “hypersexualization” of children.

Rumors about the nature of Evras have also been spreading on the internet.

De Croo said that sexual education has been provided in Belgium for half a century and warned that the country will not take steps backwards.

“It’s not new, it’s the basis of sexual health, but also the basis for our children to be are aware of their rights and (physical) integrity," he added.

Other officials sought to bat down the rumors.

“I would like to call on everyone to calm down and try once again to cut through the lies circulating about the Evras system," the education minister in the Wallonia-Brussels Federation, Caroline Desir, said Friday. “No, it does not prepare a pedophile system. No, it doesn’t plan to make children want to change gender. No, it doesn’t plan to teach children how to engage in sexual activities.”

Local media quoting the prosecutor's office in the city of Charleroi said the investigation has not established a link between the six arsons so far.

Charleroi mayor Paul Magnette compared the arsons to a "form of terrorism.”

“These are arson attacks on schools, which are sacred places,” he told Sudinfo media. “They are places where children learn respect and tolerance.”

According to local media, two other schools, in the city of Liege, also in Wallonia, have been vandalized.