Third school knife attack in Poland in a week injures three in Warsaw

A third knife attack at a Polish school in a week has injured three people, days after two earlier attacks left one dead and several wounded.

• Police arrested a 21-year-old student in Warsaw after she injured three people, including a 17-year-old girl, with a dangerous object.
• Two earlier knife attacks this week injured nine people and killed a school caretaker.
• Police detained 76 people and checked nearly 50,000 schools across Poland after the earlier attacks.
• Interior Minister Marcin Kierwiński said a 17-year-old was detained after stating he planned to harm someone at school.