Water scarcity is a major issue in Iran, particularly in arid provinces in the country's south, with shortages blamed on mismanagement and overexploitation of underground resources as well as the growing impact of climate change.

On Saturday, the national meteorological service said Iran was experiencing its hottest week of the year so far, with temperatures exceeding 50C in some areas.

"People should conserve water to avoid drops in pressure," said Tehran city council chair Mehdi Chamran, according to the ISNA news agency.

Authorities across Iran have issued similar appeals in recent days, asking residents in several provinces to limit water usage.

Tehran's provincial water management company called to reduce usage by "at least 20 percent" to help ease the shortages.

In a statement, it said that "the reservoirs of the dams supplying water to Tehran are currently at their lowest level in a century" following years of steady decline in rainfall.

Javan, a conservative newspaper, reported on Saturday that authorities had reduced water pressure in parts of the capital in a bid to mitigate the crisis, resulting in "water outages lasting between 12 and 18 hours" in some areas.