A teaching union is calling for signs in schools warning parents violence against staff will not be tolerated.
Teachers are worried about violence from pupils and teachers
The NASUWT teachers' union wants an extension of a scheme in Wrexham, north Wales, where more than 60 schools are to have the warning signs put up.
Paul Howard Davies, a science teacher at a Wrexham secondary, put the idea to the union's AGM in Brighton.
He said metal detectors and CCTV should also be fitted in schools to deter vandalism and bullying.
The teaching union wants to see all UK schools have the warning signs which have been developed in Wrexham by a partnership between the education authority, unions and the police.
A spokeswoman for Wrexham Council said the signs were being finalised in preparation for being sent to every school in the county, including infants, juniors, secondary and grant-aided schools.
Mr Davies proposed the motion at the NASUWT conference on Friday, calling for tighter security measures.
He said: "Serious violence is on the rise but the number of extreme incidents is mercifully small.
"However, if schools do not tackle with determination so-called low level disruption they face possible behaviour meltdown."
Mr Davies also described how he had confiscated laser pens from four pupils, adding that teachers were concerned these lasers would cause permanent damage if shone into their eyes.
"Some of these laser pens you can buy in the market," he said.
"If they are shone in your eyes for long enough and they are powerful enough they can cause permanent damage.
"Schools have got to be open and they have got to be welcoming places. But the bottom line is that staff and pupils have to be safe and secure."
Mr Davies said he had reported the lasers incident to Wrexham Council, which had then closed down the market stall that had sold them.
Wrexham Council was unable to comment on the claim that it has closed down the market stall.
But the authority's chief education officer, Merfyn Lloyd Jones said: "Teachers have told us that on occasions parents can be confrontational towards them resulting in them feeling threatened and intimidated.
In response , he said a verbal and physical abuse guide which includes placing signs in schools to ensure that everyone is aware that abuse towards teaching staff would not be tolerated has been produced.
This week, Dyfed-Powys Chief Constable Terry Grange called for education departments to review the way they consider allegations against teachers.