In a Twitter post, the Sindicato de Estudiantes demanded smaller classes and for more teachers to be hired. The students are scheduled to strike on September 16, 17 and 18.
The Spanish education ministry has yet to issue its final recommendations for the start of classes. The education minister, Isabel Celaá, will meet representatives from the regional governments on Thursday to agree the final safety measures and procedures to be put in place.
In an interview with a Spanish radio on Wednesday, Celaá suggested that children from 6 years of age will have to wear masks while at school, that a "bubble system" will be put in place and that classes will have to be ventilated and disinfected regularly.