Eleven pupils have been suspended from a school after they walked out saying there were too many supply teachers.
Pupils are concerned about the number of supply teachers
There have been protests at Berryhill Sports College and High School in Stoke-on-Trent on Monday and Tuesday, with dozens said to be involved.
Chairman of the governors, Terry Crowe, said the 11 pupils, who are aged about 15, were told to stay away for two weeks.
"Parents who have taken part with the children are irresponsible," he said.
Police were called during a protest on Monday, a spokesman for the school in Bucknall said.
Head teacher Ruth Poppleton said pupils were getting a good education.
"I think some pupils quite rightly are concerned we are having some supply teachers in school.
"I think it shows some pupils are worried about the quality of their education."
One of those to have been excluded, Nikita Bailey, told the BBC that about 60 pupils were involved in Monday's demonstration.
She said: "All the students are just getting to the point where they don't want supply teachers any more.
"They just want a proper education with proper teachers and everyone's just getting sick of it, so we just walked out to get heard really.
"The teachers and the head teacher won't listen to us and we thought we would get heard if we walked out."
One parent who was outside the school on Tuesday, Mandy Moore, said: "I believe the children have a right (to protest). Nobody seems to be listening."
The school said those who have been excluded were the protagonists and some issues had been resolved.
Mr Crowe said staff had said there had been complaints over school uniforms and body piercing.
The school said it could not give specific reasons why pupils had been excluded but it was not aware of an issue to do with uniforms.
Mr Crowe said: "I've been the chairman of governors for 20 years and I won't be bullied by children or parents to do things I don't think are compatible with what the school is about.
"Staff have got a hard enough job these days without parents egging them on. It's not good for school discipline."
The school said it was available to listen to the views of parents and students.
Deputy head Mark Ranford said: "A small number of pupils engaged in an unacceptable demonstration against school rules at the school gate.
"Four representative pupils were invited into the school and discussed with senior staff ways of resolving their issues.
"Several students then returned to lessons as normal. The vast majority of students enjoyed a normal school day."
The school said a meeting had been arranged with the chair of governors later this week to allow further dialogue between students, parents and senior staff.
The city council said it was concerned about the situation but the issue of school discipline was a matter for the head teacher and the governors.