Teachers in Iran marched in several cities, including Tehran, to demand fair wages, better working conditions, and the release of their jailed colleagues.
The Iranian Teachers Unions Coordination Committee stated that teachers organized protests in front of the education departments' headquarters in about 50 Iranian cities.
The committee's spokesman, Mohammad Habibi, wrote on Twitter that the security forces had arrested 70 teachers in Tehran.
The committee said that due to the security measures in Qarni Street, the security forces prevented gatherings and arrested about 40 teachers, and transferred them to a detention center.
One of the detainees was an 80-year-old retired teacher. Later, a spokesman announced that the authorities released all 70 detained teachers.
In its statement, the Coordinating Committee demanded the immediate release of all detainees and the dismissal of the minister of education.
Earlier this week, an Iranian court convicted and sentenced Rasoul Badaghi, a member of the teachers' union, to five years in prison and banned him from residing in the capital, Tehran, or its neighboring provinces.
Badaghi was arrested last November after participating in a protest. He is among the former detainees of the Green Movement protests against electoral fraud in the 2009 presidential elections.
Badaghi was convicted in September 2009 and sentenced to six years in prison on charges of "propaganda against the regime."
The government and the parliament are facing criticism from lawmakers for their inability to curb price hikes.
Iranian President Ebrahim Raisi and Speaker Mohammad Bagher Ghalibaf blamed the previous government for the price hike.
Teachers chanted slogans against Ghalibaf, a former commander of the Iranian Revolutionary Guards Corps (IRGC).
Ghalibaf is facing criticism after photos of his wife, daughter, and son-in-law showed them at Istanbul airport.
The pictures were taken after an issue between the airline crew and Ghalibaf's daughter, who insisted on passing a shipment consisting of the baby's clothing.
Ghalibaf's eldest son, Elias, wrote on his Instagram account that the trip was undoubtedly an "unforgivable wrongdoing" given the economic conditions of the people, but he denied reports that the visit was to buy baby supplies.
The IRGC's Fars news agency said that the Ghalibaf family's visit to Turkey was not to buy baby supplies, asserting that the Speaker opposed his family's travel.
The reformist "Ibtikar" newspaper published a cartoon of the Speaker, while another daily demanded Ghalibaf to submit his resignation.
The case even divided the Speaker's allies, and his media advisor criticized what he described as including the "children's mistakes in the parents' record."
A video circulated online of a televised debate between Ghalibaf and former President Hassan Rouhani during the 2017 presidential elections.
During the debate, Ghalibaf blamed Rouhani after a minister's daughter imported children's clothing from Italy.