A teenager has been charged with three counts of attempting to cause grievous bodily harm after three people were injured at a secondary school in Sheffield, South Yorkshire police said. The 17-year-old boy, who cannot be named for legal reasons, was arrested on Wednesday morning after reports of an incident involving a “sharp object” at Birley Academy. Two women in their 20s and a child suffered minor injuries that did not require hospital treatment. The 17-year-old, who has also been charged with possession of a blade or sharply pointed article on a school premises, has been remanded in custody. He is due to appear before Sheffield magistrates court on Friday. On Wednesday, police said the sharp object was believed to be a piece of broken glass. Officers said all three victims were checked over by paramedics at the scene and the child had “no visible injuries”. The school was placed into lockdown during the incident, with many parents rushing to the gates to try to collect their children. Speaking on Wednesday, school headteacher Victoria Hall told reporters: “I just wanted to thank all of our students and staff who helped manage the situation this morning, and our staff who prioritised the safety and wellbeing of all of our students.” Hall also praised the students’ “exemplary behaviour”. South Yorkshire police also praised the school staff for their actions after the “frightening ordeal”, saying they “helped keep the school community safe”. It comes just a week after two teachers and a pupil were stabbed at Amman Valley school in Carmarthenshire, south-west Wales.