The Iranian capital was hit by power outages amid protests in Tehran over worsening economic conditions in the country.
The semiofficial Fars news agency reported that Tehran was hit by a blackout for several hours on June 27, 2018, due to the "overheating" of the nation's power grid.
The Iran Power Network Management Company, a power supplier, said consumption reached a peak at 4 p.m. local time on June 26, 2018, prompting the blackouts.
The Energy Ministry has said electricity consumption has increased by some 28 percent compared to 2017.
Energy Minister Reza Ardakanian said in April 2018 that electricity output from hydropower plants would decrease because Iran was experiencing its worst drought in the past 50 years.
Ardakanian said power outages were inevitable and urged consumers to use less electricity.
The power shortages in Tehran coincided with demonstrations in the capital and other cities over the falling value of the national currency, the rial.
The value of the rial has plummeted by nearly a half in the last six months, helping feed a spiral of rising prices for everyday goods.
The currency's fall accelerated after U.S. President Donald Trump announced in May 2018 that he was pulling the United States out of Iran's nuclear deal with world powers and reinstating U.S. sanctions against Tehran.
Protesters on the streets and in Tehran's Grand Bazaar staged demonstrations for three consecutive days starting from June 24, 2018.
There were no reports of fresh protests on June 28, 2018, a day after a heavy police presence on Tehran's streets and at the Grand Bazaar.