At least 11 inmates at the prison were reported to have been hanged “en masse,” prompting a protest by inmates that led to Iranian authorities to open fire on inmates and kill at least five others, according information published by the National Council of Resistance of Iran (NCRI), or MEK, an Iranian opposition group.

Unconfirmed reports further claim that as many as 17 inmates were hanged at the prison, though only the 11 could be verified by the NCRI.

Iranian riot police are said to have surrounded several wards in the prison and also to have fired tear gas at families protesting the executions outside the complex.

That rate of executions in Iran—including the secret killing of prisoners, women, and minors—has surged since Rouhani was elected despite his promises to reform the judicial process.

Human rights groups and others have expressed outrage and concern over the rising number of executions, with some calling on the Obama administration to make it a key topic in the continuing nuclear talks with Tehran.

Maryam Rajavi, an Iranian opposition leader and president of the NCRI, condemned the mass hangings and surge in executions.

“The arbitrary and mass execution of the prisoners and opening fire on defenseless inmates reflects the savagery of the religious fascism ruling Iran on the one hand, and its vulnerability and desperation on the other,” she said in a statement released by the NCRI. “Through torture, execution, intimidation, and terror, the criminal mullahs are trying to thwart the rise in popular protests.”

Iran is believed to have executed at least 828 people since August of last year, with 313 of those being public executions. Another 515 executions were carried out but not officially announced by Iranian authorities, according to statistics compiled by NCRI.

This included the execution of at least 22 women, 13 minors, and 20 political prisoners, according to the NCRI’s Human Rights Center, which tracked a range of executions by stoning, hanging, and other methods.

Some 440 executions have taken place in 2014 alone, according to the statistics, which include both public and secret killings conducted by Iranian authorities.

NCRI’s Rajavi urged the White House to make human rights issues a main topic in the nuclear talks.

“Turning a blind eye to human rights abuses in Iran on the pretext of engaging in nuclear talks will only embolden the ruling mullahs to perpetrate more atrocities and to continue its disregard for UN Security Council resolutions,” she said.

In April, Iran attempted to execute a 26-year-old woman who was accused of stabbing her rapist after a struggle. The execution was set to take place despite claims that evidence was tampered with and the judicial process tainted.

The Iranian regime also has cracked down on journalists in recent weeks, again prompting outrage from human rights groups such as Amnesty International.

“The way journalists are being treated puts everything journalism should stand for at risk in Iran,” Hassiba Hadj Sahraoui, the group’s deputy Middle East and North Africa program director, said in a statement earlier this month. “Anyone deemed critical of the authorities has been at increased risk of arrest and prosecution in recent months, creating an intense climate of fear where voicing any criticism has become a direct road to prison.”