"I don't sleep well at night even while taking pills," Hamid told AFP, as he expressed concern for his "family's health... my kids and grandchildren".

The city woke up to blasts overnight from June 12 to 13 last year as Iran's arch-enemy Israel launched an unprecedented military campaign.

The war erupted as Iran was preparing for another round of talks with the United States, which briefly joined Israel in attacking key Iranian nuclear sites.

The attacks prompted Iran to respond with drone and missile strikes, with thousands of people killed in Iran and dozens in Israel.

Iran has now resumed talks with Washington, with Iran insisting they be limited to the nuclear issue, though Washington has previously pushed for Tehran's ballistic missiles programme and support for armed groups in the region to be on the table.

Still, the outcome of diplomacy remains uncertain.

On Thursday, US President Donald Trump said that "bad things" would happen if Tehran did not strike a deal within 10 days, which he subsequently extended to 15.

In this atmosphere, Hamid is worried about his children and grandchildren.

"I've lived my life, but they haven't done anything good in their lives, they had no fun, no comfort, no leisure and no peace," he said.

"I want them to at least experience life for a bit. But I'm afraid they might not get the chance."

Others share his concerns.

Hanieh, a ceramist from Tehran, thinks war will occur "within 10 days".

The 31-year-old has stored some essentials at her home to get through a possible military attack by the United States after its build-up in the region.

"I am getting more scared because my mother and I had lots of difficulties during the past 12-day war," she told AFP. "We had to go to another city."

Mina Ahmadvand, 46, also believes another conflict is in store.

"I think at this stage, war between Iran and the US as well as Israel is inevitable and I've prepared myself for that eventuality," the IT technician told AFP.

"I bought a dozen canned foods including tuna fish and beans as well as packs of biscuits, bottled water and some extra batteries, among other things."

- 'Lessons learnt' -

Iranians are applying "the lessons learnt during the 12-day war", Hanieh said, as windows taped up with duct tape can be seen across Tehran.

Supreme leader Ayatollah Ali Khamenei has warned that any military campaign against Iran would lead to a "regional war".

Tehran has repeatedly said it would target Israel and US bases in the region, as when it attacked a US base in Qatar during the 12-day war.

The situation has forced Iranians to follow the news closely, and only adds to anxiety over surging prices and the plunging national currency following widespread protests.

On Saturday, the euro was trading at above 1.9 million rials while the US dollar surpassed the 1.6 million mark.

For Hanieh, there has been a sense of "life on hold" since the mass protests and Iranian communications shutdown that lasted nearly three weeks.

But in Tehran, shops and offices remain open, even though cafes and restaurants are mostly closed for the month of Ramadan, which started on Thursday in Shiite Iran.

Meanwhile, Ahmadvand is preparing for the worst.

"I don't want war to happen, but one should not fool around with the realities on the ground."