An Iranian official called for mask-wearing to be made compulsory as the country on Wednesday reported its highest daily coronavirus death toll in more than two-and-a-half months.
"It is certainly required that the wearing of masks becomes mandatory," said Deputy Health Minister Alireza Raisi.
"If we use masks, especially in closed spaces and gatherings, we can very much reduce the virus' spread," he added in remarks broadcast on television.
Iran reported its first COVID-19 cases on February 19, and it has since struggled to contain the outbreak at the death toll nears 10,000.
It has refrained from imposing a mandatory lockdown on people to stop the virus' spread, and the use of masks and protective equipment is optional in most areas.
The Islamic republic closed schools, canceled public events, and banned movement between its 31 provinces in March, but the government gradually lifted restrictions from April to try to reopen its sanctions-hit economy.
Official figures have shown a rising trajectory in new confirmed cases since early May, when Iran had hit a near-two month low in daily recorded infections.
Health ministry spokeswoman Sima Sadat Lari said on Wednesday that the 133 fatalities in the past 24 hours brought the country's overall virus death toll to 9,996.
That made it the deadliest day in Iran since April 6, when the government reported 136 virus fatalities.
It was also the sixth consecutive day that Iran has reported more than 100 virus deaths.
Lari added that Iran's virus infection caseload had jumped by 2,531 to a total of 212,501 in the past day.
There has been scepticism at home and abroad about the country's official COVID figures, with concerns the actual toll could be much higher.