Unannounced Ofsted inspection at Yardley Starbank school
Ofsted have carried out unannounced inspections at a school as teachers staged a second walkout over safety concerns.
Some staff at Starbank Secondary School in Birmingham have said they receive little support from bosses in confronting badly-behaved pupils.
The education watchdog was at the school on Tuesday and Wednesday.
There was no picket during Wednesday's strike while union members met with city council representatives.
About 30 members of the National Association of Schoolmasters and Union of Women Teachers (NASUWT) walked out on 27 June, calling for urgent action and a stronger response to bad behaviour in the school.
Teachers had complained to senior staff in February following reports a 12-inch knife had been brought into the school.
There was also a separate incident where a member of staff is said to have been assaulted.
"Teachers feel unsafe," Ann Brimacombe, the union's national negotiating official, said.
"We need clear action to be taken by the school and the local authority to make sure we start off in September with a calm, ordered school."
Parents told the BBC they felt their children were also unsafe at the school with one saying her 13-year-old daughter had been physically attacked.
"What's important is every teacher and every child feels safe in that school," Ms Brimacombe said.
The school achieved the highest possible Ofsted rating of outstanding in May 2012.
The watchdog said it will publish a report of its findings.
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