A 15-year-old former pupil killed one person and injured two others at a Polish school on Thursday, police said, just a day after a 19-year-old wounded 10 people including himself in an attack at another school. Police say they foiled another school attack on Thursday, and a day after a stabbing at another Polish school. Key points and original sources are listed below.

• A 15-year-old former pupil killed one person and injured two others at a Polish school on Thursday, police said, just a day after a 19-year-old wounded 10 people including himself in an attack at another school.S1

• Police say they foiled another school attack on Thursday, and a day after a stabbing at another Polish school.S2

• A school employee was killed and two others were injured after a knife attack in Poland - the second such incident in the country in two daysS3

• A 37-year-old woman who worked as a caretaker had died in the attack, which took place at around 0700 GMT in Leszczydol-Nowiny.S4