The Spokesman of Iran Electrical Power Industry on Monday said a shortage of fuel for power plants is responsible for blackouts in Tehran and several other cities across Iran.

In the past few days unannounced power cuts, as well as Internet disruptions, have affected many businesses, banks, homes and even caused heavy traffic jams in Tehran and Tabriz. In cold winter months more gas is consumed for heating.

Some of the country's power plants rely on gas for fuel and high consumption of gas has starved the power plants, Mostafa Rajabi Mashhadi told a local economic publication on Monday.

Domestic and industrial gas consumption in Iran amounts to 600-690 million cubic meters per day, depending on the time of the year. Iran officially says it produces 800m cubic meters of gas daily of which about 60m cubic meters is allocated to power plants for electricity production. But this level of production might be somewhat exaggerated, since it is unable to export the amount of natural gas it has committed to pump to Iraq.

Nonetheless, the Islamic authorities have repeatedly boasted in the past year that natural gas production has significantly increased in the country.

However, such claims have never been supported by facts and figures.

For example, the NIGC's dispatching director, Mehdi Jamshidi, maintained on November 20 that the total amount of natural gas consumption in Iran had reached 693 million cubic meters. But the figure given was exactly the same as the one published in the previous year, indicating no real increase.

Iran's power plants in recent months had to use the low-quality fuel oil (mazut) that Iran has not been able to sell due to U.S. sanctions, Isa Kalantari, the Head of the Department of Environment said on January 19. According to Kalantari using mazut has worsened air pollution.

On February 2, Deputy Chief of Power Generation and Transmission Company (TAVANIR) said power plants will have to use liquid fuel if domestic use of gas is not reduced.

Power cuts in winter are quite rare in Iran. "Blackouts across the country in winter do not seem normal," Morad Vaisi, Radio Farda analyst wrote in a tweet on Monday. He pointed out that the capital was usually exempted for security reasons even when power cuts were inevitable.

Ministry of Energy officials say "emergency" power cuts, two hours per day, will continue in large cities unless domestic gas consumption is reduced by 10 percent.

Some social media users claim the power cuts are meant to identify the source of massive cyberattacks that have plagued the country's infrastructures since February 8.

Deputy Minister of Telecommunications and Head of Iran IT Organization on Monday said some of the recent attacks may have originated from inside the country.

"They shut down the global Internet [to repel the attacks] but realized the source was inside the country so they cut the power district by district to find the source but could not find it," @eshghbaz1 wrote in tweet while another user claimed there are rumors that cyberattack on power management networks has caused the blackouts.