Six children have been taken to hospital after a “serious incident” at a home in Sheffield, police said.
Officers were called to “reports of concerns for safety” at a property in Gregg House Road, Shiregreen, at 07:30 BST.
An air ambulance landed in the playground of nearby Hartley Brook Primary Academy, with paramedics from the Yorkshire Ambulance Service.
Two people have been arrested, with no further details yet available.
Some residents told the Sheffield Star newspaper they thought there had been a shooting, but police have said this was not the case.
South Yorkshire Police described the incident as “ongoing”, with a cordon in place and buses being diverted from the area.
A force spokesperson said: “There will be a significant police presence at the scene throughout the day as officers continue inquiries.”