People believed discipline had worsened in recent years

The Teacher Support Network asked teachers about their experiences of classroom violence, and 433 chose to volunteer their experiences.

More than 90% said they had been verbally abused, and half physically.

One woman was strangled unconscious, another stabbed with scissors and a third knocked out by a thrown rock.

More than a third also reported vandalism to personal property such as cars, clothing and books.

The respondents were sceptical about new legislation giving teachers powers to tackle bad behaviour, doubting its effectiveness without the backing of the local authority, senior management team and parents.

A spokesperson for the support network said three incidents had involved guns of some sort.

The only one on which details were available involved a student showing his teacher a pellet gun, for which he later apologised - "but she was terrified nonetheless".

The charity's chief executive, Patrick Nash, said: "Fortunately, extreme cases of violence and abuse are rare and only 2% of calls and e-mails to Teacher Support Network focus on pupil indiscipline.

"However, for those teachers seeking our support, the effects of violence and abuse can be devastating."

Some 37% of the respondents said they had taken time off work due to their injuries or the resulting stress and depression.

Parental concern

In a separate report for the Department for Education and Skills, discipline emerged as "the key education issue" for most parents asked about recent government initiatives in England.

Mori organised eight 90-minute discussion groups in London and Manchester.

Government proposals to tackle indiscipline found favour but there was a debate about the extent to which parents could be held responsible, especially for their children's attendance.

'Boot camp'

The term "off-site provision" was misconstrued by many.

"Some believe it refers to a youth club style arrangement for delinquent children and others to a boot camp," Mori said.

"The latter is preferred in order to drive up standards of discipline."

A spokesman for the Department for Education and Skills said: "Real progress had been made in tackling serious bad behaviour in schools."

Behaviour in most schools was good for most of the time.

But Mori's report said many participants were of the opinion that it had declined over the past few years - with more reports of attacks on teachers and other pupils.

Teachers were also believed to have fewer rights to enforce order.