Tens of thousands of teachers across South Korea have protested in the streets since July amid worsening complaints over student misbehavior and harassment by parents.

On Saturday, a large protest was held near the National Assembly in Seoul, estimated by local police at 100,000 people. On Monday, tens of thousands of teachers nationwide took a coordinated leave of absence and held rallies nationwide, according to organizers — an unusual tactic used to sidestep the law that makes it illegal for them to strike in South Korea.

On Monday, when teachers also mourned the suicide of a teacher who claimed to have suffered at the hands of abusive parents, some elementary schools canceled classes, according to the Education Ministry — a rare occurrence.