Iran has become the hardest hit country in Middle East by the pandemic in terms of total cases and deaths.
Health ministry spokeswoman Sima Sadat Lari said 239 people with Covid-19 had died in the past 24 hours, bringing the total since February to 27,658.
She added that the number of confirmed cases had risen by 4,019 to 483,844 with more than 3,500 new cases reported on each of the past nine days and death toll at 235 on Monday.
Twenty-seven of the country’s 31 provinces are considered to be “red” zones where infections are on the rise, but the situation in the capital Tehran and its suburbs has been described as “critical”.
Deputy Health Minister Iraj Harirchi said on Tuesday that Tehran’s hospitals were treating almost 5,800 Covid-19 patients, 948 of whom were in intensive care units.
Mr Harirchi warned of the exhaustion of healthcare workers and medical supplies as the situation worsened in the city and other parts of the country.
While trying to curb the spread, authorities in Tehran announced that wearing a face mask will become mandatory for its 10 million residents from Saturday.
Last Saturday, they ordered the week-long closure of schools, universities, libraries, mosques, cinemas and other public institutions in the capital.
Iran has also sought to prevent Shia Muslim pilgrims travelling to Iraq for Thursday’s Arbaeen processions, which mark the end of a 40-day mourning period for the Imam Hussein, the grandson of the Prophet Muhammad.
Officials have blamed the virus’s resurgence on the failure of people to abide by health measures such as mask wearing and social distancing.
President Hassan Rouhani promised to severely punish anyone caught concealing a Covid-19 infection or failing to self-quarantine for 14 days.
He added that government employees who repeatedly failed to observe regulations could be suspended for one year, and that business could be closed down if they failed to follow rules.