Forty-two assaults by pupils on teachers were recorded in the area in the last year — compared to 34 the previous year.

Teachers’ union EIS this week described the increase of 23.5 per cent as “extremely concerning” and fear that more attacks are going unreported.

EIS West Dunbartonshire spokesman Stewart Paterson said: “We advise all members to report any assault to the police and would expect that the pupil involved is excluded from the school.

“Members are also advised to request, where appropriate, that a risk assessment is carried out and that parental assurances are sought before the pupil returns to the school.

“West Dunbartonshire has been successful in reducing the number pupils excluded from school, however in cases of assault exclusion should be used in all but exceptional circumstances. “Although we have robust reporting mechanisms within the council, I am also concerned that some assaults go unreported.” Alan McKenzie, spokesperson for the Scottish Secondary Teachers Association, added: “Once again this shows us that there is an urgent need for the Scottish government to recognise this problem and to start accepting that there is a problem, instead of claiming everything is okay.

“We think that there is probably an increase of reporting these incidents because we have encouraged our members to do so.

“What is needed I think is for the government to resurrect the old discipline task group from many years ago to provide solutions to the issue.” The figures were revealed following a freedom of information (FOI) request to Scottish councils by the Scottish Conservatives.

The reported incidents included staff being subjected to physical assaults such as punching, kicking, pushing and shoving, and verbal attacks.

In 2011/12 West Dunbartonshire recorded 40 assaults before dipping to 34 in 2012/13. Last year, the number had risen to 42 assaults. Across Scotland, the overall number of incidents last year was 1,879.

Scottish Conservative young people spokeswoman Liz Smith MSP said: “It’s important to make sure teachers feel empowered to take the necessary action and, where necessary, head teachers should not shy away from expelling pupils who are persistent, serious trouble-makers and who are preventing others from getting on in the classroom.” West Dunbartonshire Labour MP Gemma Doyle said: “Our teachers should never feel that their personal safety is threatened, and they should know that if an incident does happen, it will be taken seriously.” A council spokeswoman this week said that any incidences of aggression against staff were taken “very seriously”.She added: “A review of the policy and procedure relating to incidences of violence against staff is ongoing and as a result a new training package to support staff is being trialled in November.”