Scotland's largest teachers' union has defended its decision to stage three days of targeted strike action.
The Educational Institute for Scotland (EIS) members have taken action at schools in the constituencies of politicians close to the pay dispute.
These include areas represented by First Minister Nicola Sturgeon and her deputy John Swinney.
Mr Swinney, whose own son is affected by the strike action, said it was "inequitable and indefensible".
But EIS general secretary Andrea Bradley said the union, which rejected a new pay offer last week, had been "left with no other option but to escalate action to intensify the pressure on key decision-makers".
On Wednesday afternoon members of the NASUWT teaching union also confirmed they had turned the revised pay offer.
