In the past 24 hours, Iran registered a record 34,951 positive cases, bringing the total number of infections since the start of the pandemic to 3,758,197.
The hardest-hit country in the Middle East also recorded 357 additional coronavirus-related deaths, taking total fatalities to 89,479.
"We're going uphill on the fifth coronavirus wave," health minister Saeed Namaki told state TV, expressing his hope that the situation "would calm down in the next seven or eight days".
The record caseload is Iran's third in a week. Daily infections had hit a record of 31,814 on Monday after another high of 27,444 the Tuesday before, continuing the rising trajectory seen since late June.
Tehran's virus taskforce chief Alireza Zali also warned of the "very rapid pace" of Covid-19 hospitalisations in the capital city.
The official said Tehran, with a population of over eight million, had crossed 9,700 daily infections on Monday and warned of numbers rising even further, state news agency IRNA reported.
More than half of Iran's 448 counties are currently "red" -- the highest risk level on the country's colour-coded scale, the agency said.
Zali hoped that further vaccinations and better observance of health protocols will help "reduce crushing coronavirus waves".
Iran has pinned its hopes on vaccinations to help with the health crisis but its innoculation campaign since early February has progressed more slowly than authorities had planned.
Over 8.4 million people have received a first dose, and 2.4 million have received the necessary two jabs, the health ministry said on Tuesday.
