Iran is to impose electricity rationing in Tehran and other provinces from Monday because of a shortage of fuel in power stations, the official IRNA news agency said on Sunday.
The agency said different areas of the capital will experience two-hour power cuts on a rotating basis between 9:00 am and 5:00 pm (0530 GMT to 1330 GMT).
It said similar cuts will take place in other provinces, notably Qom in central Iran, Kerman in the southeast and Gilan and Ardabil in the north.
The state-run electricity authority said the decision to impose power cuts was taken because of "the limited supply of gas to fuel power plants" and a government decree "not to use fuel oil in some power stations".
Experts say that the use of poor quality fuel oil by power stations has caused increased pollution in several cities.
On Wednesday, the government ordered three generation plants -- at Arak and Isfahan in central Iran and Karaj west of Tehran -- to stop using such fuel to "protect the health" of Iranians.
Repeated power cuts have angered citizens of the Islamic republic in recent years, especially during the hot summer months.
In July, the authorities ordered the working hours of civil servants to be halved for several days in an attempt to save energy.
Years of Western sanctions have badly affected Iran's economy.
According to the US Energy Information Association, in 2022 Iran was the world's seventh largest producer of crude oil and it has the third largest reserves after Venezuela and Saudi Arabia.
On Sunday, IRNA reported that Shina Ansari, the country's vice president in charge of environmental affairs, will attend the COP29 climate summit in Azerbaijan, which starts on Monday.