The education minister described a wave of lethal violence in schools as a “sickness” and suggested social media is to blame.

The minister was speaking after a 19-year-old student in Esenyurt in Istanbul wounded two classmates with a knife Oct. 7. That came a day after one student died and seven were injured when a 15-year-old girl with a knife attacked students at her former middle school elsewhere in the city.

There have been five such attacks in schools in less than a month. Authorities have revealed little about the motivations of the assailants, most of them young people who have obtained either blades or in some cases firearms.

“This has become a sickness,” Education Minister Yusuf Tekin said Oct. 8, according to news website sondakika. “Police measures are not enough on their own.”

Tekin said parents need education too, especially on the need to take more care to stop access to weapons. He promised better security at school gates, alongside higher walls, more patrolling security officials, and an appointment system for anyone visiting school campuses.

“Almost 80% of our children chat over social media platforms and those are the places where violence is nourished,” Tekin said. “Technology companies must approach this with more humanity.”

Earlier in the week the minister issued a warning to unnamed forces he suggested were behind the attacks that had overshadowed Turkey’s strong performance in PISA educational achievement tests.

“I have a warning for those who committed this act and those who motivated it: In this country, despite you, despite those who want to prevent it, we will all work together to maintain the unity and solidarity of this nation; we will succeed, God willing,” he said Oct. 6 during a visit to Hakkari, according to Cumhuriyet newspaper.