Polish police have significantly increased security measures at schools after two serious knife attacks in the country, and said they have detained 76 people during the operation. Police reported that, across Poland, officers were checking the situation in schools and other education facilities. By Saturday, they said nearly 50,000 institutions had been checked and 76 people had been detained. Police also said that by 6 a.m. they had recorded 231 cases in which officers were carrying out actions based on justified suspicion of a criminal offence. The police service said the aim of the measures is to protect children, young people, and staff at educational establishments. It also stated that the operation includes continuous monitoring of social media, with officers responding to reports and checking information that could signal a threat to school safety. The heightened concern followed two incidents over the course of one week. In Ostrołęka, police said a 19-year-old student allegedly attacked a secondary vocational school with a knife on Wednesday, injuring nine people. The following day, police said a 15-year-old former primary school pupil allegedly killed a school employee near Warsaw and also injured the school director and a teacher. Police said their investigation so far has not confirmed any direct connection between the two attacks. Authorities also warned about the risk of misinformation and possible imitation of dangerous behaviour. Police said reports about an alleged online call for violence contributed to further fears among parents, students, and schools, and as a result classes were not held in 50 schools on Friday. The most affected region was Mazovian Voivodeship around Warsaw, where 45 schools were closed. Polish Prime Minister Donald Tusk ordered regular police inspections in all schools, with security services to increase oversight and respond to any new threats.