A 15-year-old former pupil has been detained after a 37-year-old woman died and two others were injured in an attack at a Polish school on Thursday, police said.
The incident occurred about 9am at a school in Leszczydol-Nowiny, in Wyszkow County northeast of Warsaw.
"Despite resuscitation efforts, the life of a 37-year-old school employee could not be saved," Masovian police said on X.
"Among the injured is the principal, who apprehended the 15-year-old. Police arrived at the scene within minutes of the report, and police operations are currently underway.”
Earlier on Thursday, Interior Minister Marcin Kierwinski said three adults had been injured in an attack "with a sharp object".
He said that in a separate incident in Sierpc in north-central Poland, police detained a 17-year-old who was planning an attack. They found two knives in his backpack.
The incident comes a day after ten people were injured in a knife attack at a vocational school for teenagers in Ostroleka in northeastern Poland, with police detaining the 19-year-old suspect, who was among those hurt, shortly after the incident.
Masovian Regional Governor Mariusz Frankowski told reporters that nine people had been taken to hospital but that none of them was in a life-threatening condition.
"The injured included five students, two teachers, and two bystanders, as well as the perpetrator, who inflicted self-harm," he said.
Police said the suspect was a student at the school and that he had attacked people with a machete.
Bomb disposal experts were called to the scene. National Prosecutor Dariusz Korneluk told private broadcaster TVN24 that a homemade explosive device that nearly detonated was found in the attacker's backpack.
Fire brigade spokesperson Adrian Stupski told local media that students had barricaded themselves into classrooms in self-defence before they were evacuated.
Police said they detained the suspect about 20 minutes after the attack and posted a photo on X showing a man they appeared to have apprehended lying face down in a wooded area.
Town hall spokesperson Katarzyna Ogniewska told reporters that all schools in Ostroleka were closed and that children were safe.
The motives behind the attack were unclear. Such incidents are rare in Poland, but in September police detained a 13-year-old suspected of planning an attack and found a knife in his bag.