NUT and NASUWT union members at John Gulson school in Coventry began a two-day strike on Tuesday of this week.
This follows a successful three-day strike last week.The teachers are fighting excessive observations and an unfair appraisal policy.
NUT union members at Dormers Wells Junior School in Southall, west London, were set to strike over observations on Wednesday of this week.
Teachers plan a further walkout on Wednesday and Thursday of next week. They are fighting excessive observations that have led some workers to resign.
The NUT union has suspended planned strikes at Uplands junior school in Leicestershire as an investigation gets underway.
The investigation is into a grievance lodged by workers against head teacher Tim Luckcock and chair of governors Abid Matak.
Teachers in the NUT struck last week against plans to sack eight teaching assistants.
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