Poland stabbings driven by online glorification of violence, Tusk says

The prime minister said the attacks were acts "nihilistic violence" associated with the extreme right."Some of the people detained are active in the ultraright environment," he said, adding that police had noticed a rise in online searches of Nazi content as well as of "mass killers who have become idols online".On Wednesday, a 19-year-old student attacked and injured nine people at a vocational school in the central Polish province of Mazovian.A day later, the 37-year-old caretaker was killed after a 15-year-old entered a primary school in Leszczydół-Nowiny, north of Warsaw.Interior Minister Marcin Kierwiński also said a 17-year-old was detained in the town of Sierpc, north-west of Warsaw, after allegedly stating "on school grounds that he planned to do something... dangerous - that he intended to harm someone".Thousands of Polish ‌police officers visited schools nationwide to try to reassure pupils after the stabbings sparked rumours of a "Bloody Friday" of more attacks stemming from a supposed online challenge.Meanwhile, Polish security services convened a special meeting on Sunday after receiving information about a potential attack on Tusk and Defence Minister Wladyslaw Kosiniak-Kamysz, a spokesperson said.A special services spokesman said officials were treating the threat as "deadly serious".