Some Iranians fear the regime is now more entrenched - and ready for revenge

They are still there. There is no evading the simple fact. Everywhere the people walk. Wherever they drive. Whenever they switch on the television. The faces of assassinated leaders, and those of new rulers, dominate the public space.

Protests have come and gone. A war. Then a ceasefire. But the regime of the Islamic Republic has endured.

In fact, according to Iranians the BBC has spoken to inside the country, far from being weakened the regime is more deeply embedded. And it is in a vengeful mood.

Sana and Diako - not their real names - are a young couple living in Tehran. They are middle class, educated, the kind of people who want to see the end of hardline religious rule.

To tell their story it is necessary to exclude so many of the details that might give you an idea of their characters and lives. This is because such details can be used by the regime to track people who dare speak freely to the foreign media.

The journalist assisting the BBC in Iran met Sana and Diako near a park where families were walking with their children, making the most of this period of ceasefire.

Diako wants to believe that life will get better. "Things will change," he says. "It's already changed."

Sana laughs as he says this.

"Changed?" she asks. "It's fallen into the hands of the Revolutionary Guards. The country is a mess." Sana has felt her own emotions change since the US and Israel attacked Iran.

"At the beginning, I did not want the war to happen... [But] through the middle of the war, as long as they were targeting key figures, I was genuinely overjoyed with every one of their deaths."

But as the war dragged on, it dawned on Sana, as it did for the Trump White House, that the loss of the Supreme Leader Ayatollah Ali Khamenei and other senior figures did not usher in a new regime more amenable to compromise.

"So many of their people are still standing. What I had imagined did not come true. Everything got worse. And we are left with the Islamic Republic. I am gutted that they won this war."

It is impossible to tell the scale of support for the regime across Iranian society. There are regular public displays of solidarity organised by its supporters. By contrast opposition rallies are banned.

Our trusted sources in Iran spoke with opposition activists, human rights lawyers and independent journalists and found a mood of foreboding. There is a recurring fear: once the war is finally over the state will escalate its campaign of internal repression.

According to the Washington-based Human Rights Activists News Agency (HRANA), more than 53,000 were arrested during the anti-regime protests last January, and before the outbreak of the war. Since the war began, many thousands more are believed to have been detained.

There has also been a record number of executions of political detainees - 21 people hanged during the war. It is the highest number in such a short period for over 30 years. Nine of those hanged were connected to the January protests, 10 were for alleged membership of opposition groups, and two were accused of spying.

Susan - whose name we have changed - is a lawyer working with detainees and says conditions in prison have become much harsher. "Before the war, harsh treatment was reserved for those who were leading the protests, who had Molotov cocktails, or who were armed. But during the war, that harshness has intensified significantly," she says.

Her personal story illustrates how the conflict is dividing some families. Her parents are openly pro-regime and she worries they might be targeted if the government was to be overthrown. When she expressed this fear to her brother, who is anti-regime, his reply was chilling: "Since they want to be martyred, why deny them that right?"

Susan wants the war to end but is certain that people like her will come under even greater pressure. And she is fearful for the fate of detainees. "I think that if the war ends, the regime will probably take out its rage from this war on the prisoners. I think we're living on borrowed time."

Human rights activists reported four executions so far this year of people accused of links to the Mossad, Israel's foreign intelligence service.

Independent journalists are among those who fear being targeted by accusations that they are helping the United States or Israel. There have been numerous arrests of people accused of sending material to foreign media seen as hostile to the state.

One journalist - we are calling him Armin - who spoke to our Tehran colleague told of how just reporting the facts of the war was enough to be arrested, with potentially fatal ramifications.

"Before, we might be accused of a political offence. But in the current wartime conditions, if we report on the war, we could be accused of espionage." A charge of spying carries the death sentence in a court system that does the regime's bidding.

"Before, we were trying to understand how many people had been harmed or what impact the protests would ultimately have," explains Armin. "But now it's different. Now we're focused on staying alive - ourselves and our families."

While his family tries to sleep, Armin is restless.

"I lie awake wondering what the future holds. And that uncertainty brings with it terrible anxiety."

Little surprise that the opposition has vanished from the streets. The regime is master of life and death.

With additional reporting by Alice Doyard