Forty days after the first protesters were killed in Iran’s worst unrest in decades, Iranians took their grievances against the government to cemeteries on Thursday, marking both the end of the traditional mourning period and their determination not to back down.

Over four days of protests in November, security forces shot and killed up to 450 people, human rights organizations estimate, and in the weeks leading up to Thursday, some of their survivors called on the public to join them in yet another act of defiance: at the graveyards of their loved ones.

Iran’s leadership was not having it.

Even before the end of the mourning period, the authorities began cracking down, beefing up security in cities across the country, renewing their disruption of the internet and conducting waves of pre-emptive arrests.

Then on Thursday, uniformed security forces and plainclothes militia deployed en masse across the country to keep people off the streets.