Iran has arrested nearly 40 teachers across the country before and since the May Day protests, Human Watch Rights said, calling for their release.

Quoting the reformist emtedad news site, the watchdog said that as of May 1, Iranian authorities had arrested 38 teachers.

At least 17 of them are still detained, including Mohammad Habibi, spokesman for the Iranian Teachers Association (ITTA), the watchdog reported on Thursday.

He said the arrests came after the Coordinating Council of Iranian Culture Teachers Associations called for a nationwide protest on May Day, the eve of National Teachers’ Day.

“The Iranian authorities have once again decided to lock up people who seek to organize themselves to assert their collective rights instead of working with independent associations to ensure respect for the economic and social rights of Iranians,” he said. Tara Sepehri Far, senior researcher at HRW.

“Attempting to silence peaceful mobilization and protests will not make Iran’s sad economic reality go away,” she added.

Iranian teachers have taken to the streets several times in recent months to protest the conditions and the arrest of colleagues.

Teachers have been asking the government for months to speed up reforms that would see their salaries better reflect their experience and performance.

In April, an Iranian court sentenced teachers’ union activist Rasoul Bodaghi to five years in prison for “illegal assembly” and “propaganda”.

The Norway-based Iranian human rights NGO said at the time that Bodaghi had been sentenced for “the intensification of repression against civil society in Iran”.

Iran has suffered from tough economic sanctions, reimposed by the United States in 2018 after Washington unilaterally withdrew from a deal with world powers over Iran’s nuclear program.

The Islamic republic has seen inflation soar to over 40%, taking a heavy toll on the living standards of public sector workers and other people on fixed incomes.

According to HRW, Iranian authorities have cracked down on “militant teachers” since the start of the Iranian New Year in March.

More than a dozen have been summoned for questioning and several arrested, while others have been charged, convicted or imprisoned.

Endangering “national security” was usually the main charge against them.