Iran's health ministry on Monday reported 13,890 new COVID-19 cases over the past 24 hours amid the spread of the mutated strain, raising the total number in the country to 1,945,964.
Earlier in the day, the Iranian health minister announced that cities expect the resurgence of one of the "most terrible" COVID-19 waves.
The pandemic has so far claimed 63,332 lives in Iran, up by 172 in the past 24 hours, said Sima Sadat Lari, spokeswoman for the Iranian Ministry of Health and Medical Education, during her daily briefing.
Of the newly infected, 2,048 were hospitalized, Lari added.
A total of 1,658,978 people have recovered from the disease and been discharged from hospitals, while 4,095 remain in intensive care units, she noted.
According to the spokeswoman, 13,183,709 tests for the virus have been carried out in Iran as of Monday.
The fourth wave of the epidemic is progressing rapidly from the west to the east of the country, Lari said, advising people to use masks and refrain from gatherings, parties, weddings and mourning ceremonies.
Currently, 88 Iranian cities are on red alert for a high risk of infection, while 139 others on orange alert for a medium risk, the spokeswoman said.
Iran reported the first cases of COVID-19 in the country in February 2020.