A school welfare officer has been seriously injured in a stabbing at a school near Scunthorpe.
The 61-year-old woman was attacked at about 09:00 BST at Winterton Community Academy.
Humberside Police said a 16-year-old girl has been arrested on suspicion of attempted murder and is being questioned by officers.
The force said the woman is being treated in hospital for “serious but not life threatening injuries”.
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Neither the school nor police gave further details about the victim or her injuries.
Ch Supt Christine Wilson said: “There was no disruption to any other children, none of whom witnessed the incident.
“Children at the school have not been directly affected by this.”
Headteacher Gareth Morris said: “We are keen to reassure parents and the community that this is an isolated incident and that the school remains open.
“We will support our staff directly affected and will be keeping parents updated throughout the day.”
Winterton Community Academy, formerly Winterton Comprehensive School, has 518 pupils aged 11 to 16-years-old.