A child under the age of 10 was found with a knife on a school premises, information from Cleveland Police has revealed.
Statistics uncovered in a Freedom of Information request to the force found that 12 incidents with pupils having weapons on them were reported in the force area going back to 2013.
The youngster below aged 10 found with a knife was not arrested by officers.
In 2013, a 13-year-old was found with a point or blade while on school premises, while in the same year a 16-year-old was found to be in possession of an offensive weapon on a school site.
In total there were 12 incidents of children having weapons at schools in the Cleveland force area since 2013.
Cleveland recently held a knife amnesty so that weapons could be handed in.
A Cleveland Police spokeswoman said: “There have been 12 reported offences over the last four years across Cleveland.
“Our neighbourhood police officers work closely with local schools and their pupils to raise awareness of the dangers of knives and this runs alongside our force-wide campaigns, such as our recent knife amnesty.”
National Police Chiefs’ Council Lead for Knife Crime, Chief Constable Alf Hitchcock, said: “Schools should be free of weapons and all children should be able to learn without fear or violence.
“Carrying a weapon of any kind in schools is not an issue for a school to deal with alone; police and partners will always be willing to work with them and take appropriate action.
“We have recently seen an increase in young people carrying knives and this is worrying.
“We are responding to this trend by targeting those who carry them illegally and working with retailers to reduce the sale of knives to underage people through nationally coordinated operations.
“Police involvement in schools, whether it be officers delivering talks and interactive sessions or based in schools themselves as part of the Safer Schools Partnership, helps us to educate young people and explain why carrying a weapon illegally is never acceptable.”
The figures come amid a crackdown on knife crime in schools by some forces.
Earlier this month, the Metropolitan Police announced officers would be working with schools to highlight the potential consequences of carrying a knife.
It followed the case of teacher Ann Maguire, who was stabbed to death at Corpus Christi Catholic College in Leeds in April 2014 by pupil Will Cornick, 15.