A teacher being threatened with a knife by a pupil was among almost 2,000 attacks in Bradford schools in three years.

Statistics obtained from Bradford Council by the Telegraph & Argus following a Freedom of Information request show there were 404 recorded attacks on teachers by students between 2010 and 2012, and 1,573 pupil-on-pupil physical assaults.

Other incidents involving teachers include a female teacher’s breasts being grabbed by a student, a pupil trying to strangle a teacher, a teacher being stabbed with a pen, and a teacher being punched and kicked in the stomach.

The Council said the most common pupil-on-teacher attacks were verbal abuse, kicking, pushing and biting. Weapons used in attacks on teachers include snowballs, scissors, chairs, stools, shoes and books.

The number of recorded attacks on teachers has dropped year-on-year, from 150 in 2010 to 135 in 2011 and 119 in 2012.

Pam Milner, branch secretary of the teachers’ union NASUWT, believed teachers suffered more attacks than were reported. She said: “A lot of these assaults are not reported. I think this is the tip of the iceberg.

“Schools should have robust policies so that if something happens there are sanctions available.

“There are far too many times where a teacher is assaulted and nothing happens to the child. Schools are frightened to permanently exclude because they have procedures to go through and financial penalties.

“I would encourage teachers, if they are assaulted, to get in touch with their trade unions and fill in the violence at work forms that exist in all schools, which I’m sure some teachers are not told about.”

She added: “There is no excuse for this kind of behaviour in the classroom. Just because you are a teacher, it doesn’t mean you are a punchbag.”

Councillor Ralph Berry, portfolio holder for children’s services, said: “The fact the numbers are reducing is a good sign. Occasionally we get some shocking situations and we need to make sure staff are supported.

“Any attack on a teacher has to be taken very seriously. With older children it may involve legal proceedings and potentially very serious consequences.”

The number of pupil-on-pupil attacks also dropped between 2010 and 2012. There were 646 recorded in 2010, 543 in 2011, and 384 in 2012.

Coun Berry said: “Any violent incident is unacceptable, and while the number of such incidents has fallen, we will continue to work in close partnership with schools to share best practice so this kind of behaviour is tackled. We do need to bear in mind, though, that there are more than 93,000 pupils at schools across the Bradford district and that the vast majority behave well.”

The Council would not reveal the nature of the pupil-on-pupil attacks or what weapons were used, despite a T&A request. The Council claimed it could breach student confidentiality.