Attacks against teachers and pupils, sexual misconduct and arson are just some of the reasons that nearly 800 primary school children, including 26 aged five and under, have been excluded from Bradford’s schools in the last three years.

Difficult youngsters are leaving their fellow students too frightened to attend school because of the havoc they cause, according to one teaching union, who blamed the parents for failing to impose boundaries, expectations or moral codes on their children.

Other reasons for the 788 fixed term exclusions, including 514 children aged ten and under, include racial abuse, the use of weapons including knives, verbal abuse and drug and alcohol problems.

The figures have been described as shocking by NASUWT’s Pam Milner, who said children as young as five bring cannabis into classrooms to show friends what they found at home, and those only slightly older bring in knives and BB guns. She called on the government to give Bradford Council more money to tackle the problem “I am shocked it is happening,” she said. “These children are causing mayhem in school and parents need to get a grip. I know other children in their class are very frightened to go to school. I think when parents start voting with their feet and take their children out of school where others are causing mayhem something might be done about it. It is symptomatic of a broken society where boundaries are not there.”

The figures, released under a Freedom of Information request, show that 256 youngsters, aged between four and 11 years old, were excluded in 2009/10, 274 in 2010/11 and 258 in 2011/12. The exclusions range from one day up to 45 days a year.

The main reason was physical assault against a pupil, followed by physical assault against an adult, persistent disruptive behaviour and then a combination of the other reasons.

The figures are for 153 primary schools and four behaviour centres, linked with certain primary schools. The figures do not include the Primary Public Referral Unit or Bradford’s specialist school provision The figures included 42 five and six year olds, 52 six and seven year olds, 89 seven and eight year olds, 151 eight to nine year olds, 180 aged between nine and ten and 248 ten and 11 year olds.

Anne Nash, branch secretary from the ATL, said that she knew of a high level of disruptive youngsters who jeopardised other children’s education because so much time and effort was spent on them.

“Nobody wants to exclude any child, but we are protecting other children,” she said. “Lessons are being disrupted more than they used to be partly because places that used to be there for children are no longer there and there are a high level of disruptive children in mainstream schools.We are trying to solve society’s problems.”

Councillor Ralph Berry, the executive member on Bradford Council for Children’s Services, said that the figures were a worry and that the Council was looking at reorganising the way some special advice services were given to schools.