A police officer can take a child into police protection without going to court if they have reasonable cause to believe the child would otherwise be likely to suffer significant harm. The officer must tell the local authority, the child (if old enough to understand) and the parents, and a designated officer must look into the case. No child can be kept in police protection for more than 72 hours (section 46(6)). If longer protection is needed, an emergency protection order can be sought.
People often call it a "police protection order" or PPO, but it isn't a court order. It is a police power.
Working Together 2026 (paragraph 287 and chapter 3, Immediate protection) says police powers should only be used when necessary, in exceptional circumstances where there isn't time to get an EPO, and that wherever possible the decision to remove a child from a parent or carer should be made by a court. It can be used when the harm comes from outside the home as well as inside it.
For schools: if you think a child is in immediate danger, call 999. If a child is taken into police protection from school, record what happened and who collected the child, and tell children's social care if the police haven't already.