A 21‑year‑old woman has been detained after injuring three students and a school worker with a knife at a Warsaw school, the third such incident in the country this week.

The attack, which targeted a 17‑year‑old girl, came a day after police patrols were sent to hundreds of schools across Poland following two other stabbings, one of which resulted in the death of a 37‑year‑old caretaker.

Polish authorities said the victim was taken to hospital but her condition was not life‑threatening. Two other women, aged 17 and 24, who had been submitting enrolment paperwork, were also injured.

Police have not confirmed whether the latest assault is connected to the previous attacks, though some reports suggest an online challenge may be involved.

In the week leading up to the incident, a 19‑year‑old student wounded nine people at a vocational school in Mazówie, and a 15‑year‑old student entered a primary school in Leszczydół‑Nowiny, north of Warsaw, where the caretaker was fatally stabbed.

Polish Prime Minister Donald Tusk underscored the need for uncompromised safety in schools, while Interior Minister Marcin Kierwiński highlighted a recent detention of a 17‑year‑old after warning of violent intentions.

The authorities have detained 76 individuals after deploying to schools nationwide. The government calls for a coordinated response to curb knife crime and protect students.