GEOFF BENNETT: Today, Iran announced it would suspend cooperation with the U.N.'s nuclear watchdog, possibly preventing an independent review of the damage done to Iran's nuclear sites and setting Washington and Tehran on a collision course.

Iranian officials say they aren't closing the door to diplomacy, but say there are no plans for talks with the U.S. AMNA NAWAZ: In the meantime, the Iranian government has launched a massive crackdown since the war with Israel and the U.S. ended.

The crackdown is ostensibly meant to find Israeli spies, but Nick Schifrin spoke earlier today with an Iranian Nobel peace laureate, who describes a harsh stifling of all dissent.

NICK SCHIFRIN: In Tehran today, the regime is stalking its enemies, hundreds of arrests, alleged Israeli collaborators paraded on state TV, and checkpoints around the country.

NARGES MOHAMMADI, Nobel Peace Prize Laureate (through translator): In times like these, the Islamic Republic uses every tool at its disposal to intensify its repression of the Iranian people.

NICK SCHIFRIN: For 30 years, Narges Mohammadi has fought for democracy and human rights, and in 2023 won the Nobel Peace Prize in absentia.

She's banned from travel and has been repeatedly arrested.

Most recently, she was held in Iran's notorious Evin prison and was released in December on house arrest, where she spoke with us today.

NARGES MOHAMMADI (through translator): The Islamic Republic is now using the war with Israel as a pretext to intensify its crackdown.

NICK SCHIFRIN: Israel's 12-day campaign against Iran facilitated by a massive intelligence penetration across society, and now Iran says it's hunting for Israeli spies and their weapons of choice.

NARGES MOHAMMADI (through translator): I witnessed Islamic Revolutionary Guard Corps forces in Tehran stopping cars and dumping all the passengers' belongings into the street, supposedly while searching for drones.

It's an insult to the intelligence and dignity of the Iranian people.

NICK SCHIFRIN: And Mohammadi says the regime is extending its repression of the Women, Life, Freedom movement launched following the 2022 death of Mahsa Amini in police custody after she was arrested for not wearing a headscarf.

NARGES MOHAMMADI (through translator): Over the past few days, I have received reports that even women sitting quietly in cafes wearing headscarves, but not full veils, were confronted by armed guards who stood over them and ordered them to cover more fully.

This shows that the Islamic Republic is now using this opportunity to intensify its campaign against women.

Civil society activists, especially women's rights defenders and media figures, are under intense pressure.

Many have been summoned for questioning, visited by security forces.

Their families and lawyers have no information about their whereabouts.

The regime claims it is cracking down on spies, but, in reality, it's suppressing the democratic movement.

NICK SCHIFRIN: Human rights groups say, since Israel attacked on June 13, Iran has executed at least six people for spying for Israel.

And Iran's Parliament fast-tracked a bill that would allow punishing espionage or cooperation with hostile governments with the death penalty.

NARGES MOHAMMADI (through translator): If enacted, it will dramatically expand the scope and frequency of executions in Iran.

We're likely to see more prisoners placed on death row.

The consequences of this law will be extremely severe.

NICK SCHIFRIN: On June 23, Israel targeted Evin prison.

Iranian authorities said more than 70 were killed inside.

Many political prisoners were evacuated.

NARGES MOHAMMADI (through translator): After the bombing, it was the Islamic Republic's security and military forces that imposed harsh measures on the prisoners.

They were handcuffed, blindfolded and placed under heavy guard with snipers watching over them.

Overnight, they were taken out and transferred under extreme security conditions to some of the worst prisons in the country.

NICK SCHIFRIN: And what are the conditions that those prisoners face today since they have been moved?

NARGES MOHAMMADI (through translator): The women were taken to Qarchak Prison, where I spent several months.

I know firsthand how intolerable the conditions are there.

There are no proper health care facilities.

Their situation is deeply alarming.

There isn't even safe drinking water available.

I have received very disturbing reports about the men who were transferred to the Greater Tehran prison.

There's no access to clean drinking water.

We fear that prisoners could die from lack of water, food and medical care.

NICK SCHIFRIN: Over the 12-day war with Israel, Iranian authorities now say nearly 1,000 people died.

Many more were wounded.

In general, how are Iranians coping today?

NARGES MOHAMMADI (through translator): After the 12-day war, the Islamic Republic did nothing to improve the lives of the people, despite the immense suffering they endured.

The regime shows no real concern for the public's hardship.

Instead, it continues to expose people to even greater repression.

During the 12-day war, I was in Tehran.

The city was under attack day and night, and we had no refuge.

The Internet was cut off and we lost contact with many of our friends and even with our families.

We were caught between two fronts, the Islamic Republic's longstanding war against the Iranian people and a military conflict with Israel.

Yet, despite all this, the Iranian people continue to demand peace, prosperity, development, freedom and democracy, carried out through the will and agency of the Iranian people.

NICK SCHIFRIN: An Iranian will that in the past has demanded democracy, but is now handcuffed.

For the "PBS News Hour," I'm Nick Schifrin.