By Pawel Florkiewicz and Alicja Surdy
WARSAW, Oct 9 (Reuters) - Thousands of Polish police officers visited schools nationwide on Friday in an effort to reassure pupils after two teenage stabbing sprees in as many days sparked rumours of a "Bloody Friday" of attacks.
Social media in Poland has been filled with talk of a supposed online challenge that could be behind the attacks and which would end with a bloodbath at schools on Friday, but police said their investigations had found no evidence of this.
By midday, 24,000 police officers had been deployed to 15,000 schools and 19 young people had been detained, mainly for making threats online, Interior Minister Marcin Kierwinski said.
"There will be no compromise here - the safety of youngsters is the most important thing," he told a press conference.
Education Minister Barbara Nowacka said 59 schools around the country were closed, mainly in the Mazowsze region where this week's attacks took place.
On Thursday, a 15-year-old former pupil wearing a helmet-mounted camera killed one employee and injured two others at a Polish primary school in Leszczydol-Nowiny, northeast of Warsaw. On Wednesday, a 19-year-old wounded 10 people including himself at another school in Ostroleka, north of the capital.
The scale of the police deployment and the school closures underscored the shock caused by two attacks in a country where school stabbings have been very rare, and the speed with which online rumours amplified the fear.
ONLINE THREATS AND DISINFORMATION SOW TERROR
In Ostroleka, schools were operating as normal but attendance was just 25%, the PAP state news agency quoted Mayor Pawel Niewiadomski as saying.
In Warsaw, 59-year-old NGO manager and mother-of-four Dorota Czekaj told Reuters the week's events had left her "simply terrified". She called for a tough response to online content that could encourage violence.
"Unlimited access to all sorts of content, some of it very negative, certainly affects... our brains and contributes to a general social desensitisation in some way," she said. "And I think we simply have to respond to this more firmly."
Authorities warned people of the risks of online disinformation, with Defence Minister Wladyslaw Kosiniak-Kamysz suggesting Russia could use such events to sow panic.
Russia has repeatedly denied attempting to destabilise Western countries using online disinformation.
Polish police made a string of arrests on Friday.
These included a 13-year-old from Warsaw who posted a photo of a knife in a class group chat and threatened other students, a 14-year-old in Warsaw detained on school grounds with a knife and firecrackers, and two 15-year-olds from Pruszkow County just outside the capital who posted a video with threats to kill.
Several social media accounts posted pictures on Thursday of a TikTok account which supposedly belonged to the attacker from Leszczydol-Nowiny and featured images taken just before the incident. Reuters was unable to find the account, which appeared to have been taken down.
"Officers from the Central Bureau for Combating Cybercrime (CBZC) are aware of the content posted on the TikTok account in question," CBZC told Reuters by email, adding that the platform was cooperating with the agency.
TikTok did not reply to an emailed request for comment.
(Reporting by Pawel Florkiewicz, Alicja Surdy, Kuba Stezycki, writing by Alan CharlishEditing by Gareth Jones)
