Iran nationwide blackouts spark protests
In footage posted to social media, protesters can be heard chanting "Death to Khamenei" and "Death to the dictator" into the night.
Scheduled cuts to power help manage the demand for a limited supply, but there have been unannounced power cuts in recent days.
One such power outage struck Tehran at 11:00 pm on Saturday night and continued until 5 a.m. in some parts of the city, the London-headquartered media outlet Iran International reported.
The sustained power cuts are taking place during an exceptionally hot summer in parts of the Middle East, when people are heavily reliant on air conditioning and refrigeration.
In some potential relief for Iranians, the Bushehr nuclear power plant resumed operation after two weeks off-grid.
However, Bushehr suffered faults on Monday morning, meaning it could not operate at full capacity. The problem has since been fixed, the plant's manager told press.
Mostafa Rajabi Mashhadi, spokesperson for state electricity company Tavanir, apologised for the power outages, according to the semi-official ISNA.
Mashhadi blamed the unscheduled outages on a sudden spike in temperatures and subsequent increase in use of cooling appliances.
IMPORTANT:— Yesar Al-Maleki يَسار (@yesar) July 4, 2021
Iranian power sector official says the gap between supply and demand is now at 11GW. #Iran is facing unprecedented electricity demand since the beginning of the year forcing state power company Tavanir to plan "outages" throughout the country, especially Tehran.#oott
Iran has said it has ambitions to supply energy across the region, and has already provided Iraq with energy. However, Tehran has since cut off its supply to its western neighbour, resulting in massive power shortages.
Energy shortages are a major source of protest in Iran.
Demonstrations took place across Iran in the winter of 2019 after the government hiked up the price of fuel. More than 100 people were killed in the resulting security force crackdown.