Thousands of weapons have been seized from schools across the country - with samurai swords, axes and air guns among those confiscated.
The majority of cases involved children, including some as young as five, according to figures released to the Press Association by police forces in England and Wales.
At least one in five incidents involved knives, while the data suggests an overall increase in the number of weapons found on school premises.
Police chiefs said there had been a "worrying" increase in young people carrying knives. They said police work with schools to help educate youngsters on why carrying any illegal weapon is wrong.
Press Association analysis of data from 32 police forces that gave figures showed there were 2,579 weapons found from the 2015/16 financial year to this year.
The number is likely to be much higher, when considering those forces that did not provide data, or offered only incomplete figures, under Freedom of Information laws.
In 2016/17 alone, among those that gave breakdowns, there were at least 1,369 weapons found - a rise of almost 20% on the previous year, despite this not covering a full 12-month period.
According to the 24 forces that gave specific details on the type of weapon, just under 500 of the nearly 700 seized were knives - including samurai swords.
It means the number of knives taken away is likely to be much higher if data from other forces about the type of weapon used is taken into account.
Other weapons confiscated included at least 26 guns, including BB guns, air rifles and an imitation firearm.
More unusual contraband included a police baton, a rolling pin, a can of beer and a 15in metal rod.
One student fashioned an improvised battery device, while another was caught with a less sophisticated device - an unwound paperclip.
At least 47 children found with weapons were below 10 years old, the age at which someone can be prosecuted.
This included three five-year-olds, one of which was caught with a knife while another was found with a missile - typically a brick or a rock.
There were also 47 cases where the person involved gave their occupation or status as teacher, or a related job, such as tutor. Forces did not give further details.
A handful of forces offered historical data that showed weapons including a guillotine, a Taser gun and a ukulele were among the items seized.
In a minority of cases, depending how information was recorded, incidents could have involved the use of body parts such as a fist, or verbal abuse.
Forces in England and Wales were asked for information on the numbers of weapons seized in schools, along with details of the incidents.
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.
The following year, teacher Vincent Uzomah was seriously injured when he was stabbed at Dixons Kings Academy in Bradford by a racist pupil.
Latest Government figures show that in 2014/15, primary and secondary school pupils in England were suspended on more than 132,000 occasions for assault or verbally abusing and threatening behaviour.
In addition, there were more than 2,100 permanent exclusions for these reasons.
Geoff Barton, general secretary of the Association of School and College Leaders, said: "Schools work closely with the police to protect and educate their pupils, and in some cases police officers are stationed in schools. Where appropriate, schools conduct searches and use metal detectors, and they implement robust disciplinary procedures against anyone found in possession of a weapon.
"Young people are taught about the dangers of offensive weapons both in lessons and in talks delivered by invited speakers."
A Department for Education spokesman said the Government had increased teachers' powers so they can take action if they suspect a pupil has brought prohibited items into school.
He said: "Teachers can also search without consent and confiscate prohibited items."