An Iranian official said Friday that 52 people had been arrested in the previous day's protests against high prices that highlighted deep-rooted economic problems in the second city of Mashhad.
Hundreds took to the streets of Mashhad, a site of holy pilgrimage in the northeast of the country, on Thursday with slogans mostly directed at President Hassan Rouhani's government for failing to tackle a range of economic problems.
The head of Mashhad's revolutionary court, Hossein Heidari, said people were arrested for chanting "harsh slogans", the Fars news agency reported.
"We consider protest to be the people's right but if some people want to abuse these emotions and ride this wave, we won't wait and will confront them," Heidari said.
Videos published by a small reformist media group, Nazar, showed people in Mashhad chanting "Death to Rouhani".
More provocatively, there were also chants of "Death to the dictator" and "Not Gaza, not Lebanon, my life for Iran" -- a reference to anger in some circles that the government is focusing on the wider region rather than improving conditions at home.
Similar yet smaller protests reportedly took place in a few other cities, responding to calls on the Telegram messaging service for a day of demonstrations to say "No to high prices".
Egg prices have doubled since last week due to the government's culling of millions of chickens diagnosed with avian flu, government spokesman Mohammad Bagher Nobakht told reporters on Tuesday.
But the reasons behind the protests were more deeply rooted, according to one local lawmaker.
"There is a major crisis in Mashhad caused by illegal financial institutions," Hamid Garmabi, who represents the city of Neyshabour near Mashhad, told Fars.
He was referring to the mushrooming of unauthorised lending institutions under former president Mahmoud Ahmadinejad between 2005 and 2013.
A poorly regulated banking sector combined with a construction boom left many credit companies stuck with toxic debts and unable to repay investors.
Since coming to power in 2013, Rouhani's government has sought to clean up the financial sector, shutting down three of the biggest new credit institutions -- Mizan, Fereshtegan and Samen al-Hojaj.
He has tasked the central bank with reimbursing lost deposits, but progress has reportedly been slow.
Mashhad was one of the worst-hit areas by the closure of Mizan, which had around one million accounts, leading to several protests in the city since 2015 according to the official IRNA news agency.
Other financial scams have also hit the region, notably the collapse in 2015 of a mega project to a build the new town of Padideh next to Mashhad, which left more than 100,000 investors out of pocket.
"The shadow of stagnation in Mashhad and Khorasan Razavi province is more than other places in the country due to the unfortunate investment events in companies such as Padideh, Mizan Financial Institution and other credit funds," a senior housing official in the province told IRNA last year.