Thousands of protesters converged in central Iran to voice their anger after the city’s river dried up due to drought and diversion.
The massive protest, that drew in farmers and other people from across Isfahan province, was the biggest since demonstrations over the water crisis started on November 9.
“Thousands of people from Isfahan, farmers from the east and west of the province, have gathered in the dry Zayandeh Rood riverbed with one key demand: let the river run,” state media in Isfahan reported, broadcasting live images of Friday’s rally.
“For years, there has been no will to resolve the problems of this important river.”
Footage aired on the channel showed men and women in a crowd spanning the riverbed clapping in unison.
“Plundered for 20 years” and “the water must return,” they chanted.
Others were seen holding up banners that read “East Isfahan has become desert” and “Our water is being held hostage”.
The city of Isfahan is Iran’s third-largest, with a population of around two million.
It is a tourist magnet due to its heritage sites, including a historic bridge that crosses the Zayandeh Rood river. But since 2000 the river has seen dry spells.
Drought is seen as one of the causes, but farmers also blame the authorities’ diversion of the river water to neighbouring Yazd province.
The Iranian government has promised to come to the aid of farmers and resolve the crisis.
“I have ordered the ministers of energy and agriculture to take immediate steps to deal with the issue,” Iran’s First Vice President Mohammad Mokhber said.
Iran is one of the most water-stressed countries in the world.
Water levels in the country’s lakes and reservoirs have halved since last year due to the severe drought affecting the country and the wider region.