Washington: The United States placed over a dozen Iranian officials on its sanctions blacklist Wednesday for the crackdown on protests over the death of 22-year-old Mahsa Amini while being held by the morality police.

The sanctions were announced as security forces opened fire on thousands of protesters who massed in Amini's hometown to mark 40 days since her death, according to Hengaw, a Norway-based human rights group.

Sanctions were placed on Mohammad Kazemi, the head of intelligence for the Islamic Revolutionary Guards Corps, and Hossein Modarres Khiabani, the governor of Sistan and Baluchistan province, the location of some of the worst violence triggered by the recent protests.

Two other IRGC officials were blacklisted, as were the police chief of Isfahan and seven national and regional prison officials.

Since becoming head of the IRGC's Intelligence Organization in June, "Kazemi has overseen a heightened crackdown on civil society across the country," the US Treasury said in a statement.

"The IRGC and its Basij militia have used lethal force against protesters and is an essential element of the regime’s aggressive use of violence against the Iranian people," it said.

As Sistan and Baluchistan governor, Khiabani was responsible for an incident on September 30 when security forces killed at least 80 in Zahedan, the provincial capital.

The Treasury and State Department also placed sanctions on two Iranian intelligence officials who allegedly operate an academy to train and recruit hackers, and a company involved in internet censorship for the government.

"It has been 40 days since the death of 22-year-old Mahsa Amini in the custody of Iran’s so-called 'Morality Police,' and we join her family and the Iranian people for a day of mourning and reflection," US Secretary of State Antony Blinken said in a statement.

"The United States is committed to supporting the Iranian people and ensuring that those responsible for the brutal crackdown on the ongoing nationwide protests in Iran are held accountable," he said.