The Health Ministry also announced 235 new fatalities from the novel coronavirus in a single day, a figure equaling the record high set nearly 10 weeks ago.
Tehran has been struggling to contain the coronavirus outbreak since it reported its first cases in February.
Health Ministry spokeswoman Sima Sadat Lari said the 235 deaths – equal to the high announced on July 28 – had brought the total number of fatalities to 27,192.
She added that 3,902 new infections were recorded from Sunday to Monday, raising the country’s overall caseload to 475,674.
After declining for weeks, the deaths and infections have been on the rise in Iran since the beginning of September.
The worsening situation caused authorities to reimpose restrictive measures in Tehran Province for a week from Saturday.
Under the new set of restrictions, universities, boarding schools, seminaries, language schools, vocational schools, educational institutions, libraries, mosques, museums, theaters, zoos, theme parks, aqua parks, swimming pools, banquet halls, wedding venues, coffee shops, tea houses and hair salons must shut down from Saturday to Friday.
“Holding any social, cultural, religious ceremonies and gatherings is also banned,” a deputy Tehran governor said.
The restrictions are largely the same as those taken early on in the pandemic by Iran, which has so far stopped short of imposing a full lockdown.
They had been progressively eased from April to avoid deepening an economic crisis precipitated by the reimposition of heavy sanctions by the United States in 2018.
President Hassan Rouhani also warned that flouters of new restrictions will be penalized.
Speaking during a meeting of the national taskforce for fighting the coronavirus, Rouhani said civil servants and businesses will face punishment if they violate the new health guidelines.
“We approved that all our civil servants in the country, whether in governmental or non-governmental sectors, and those who own a business, will be dealt strongly if they do not care about [the rules],” he noted, explaining that punishments range from a reprimand to a one-year suspension from work.
Businesses which do not abide by the coronavirus restrictions will be closed, Rouhani added.
“Anyone who feels ill, and it is clear to them that they are ill, must not hide their illness,” Rouhani said. Otherwise, he added, they will be committing “the highest offense” that will demand “the highest punishment”.
AFP and Reuters contributed to this story.