Iran announced on Sunday its highest single-day death toll from the coronavirus with 251 confirmed dead.
Health Ministry spokesperson Sima Sadat Lari said the total confirmed death toll now stands at 28,544.
Iran had just recently recorded its highest daily death toll four days earlier with 239 new fatalities.
A further 3,822 new cases were confirmed from Saturday to Sunday, raising recorded nationwide cases to 500,075. Nearly 4,500 patients are in critical condition.
Among those recently infected is the head of the Atomic Energy Organization of Iran, the latest senior official to test positive for the virus.
Ali Akbar Salehi, who is also a vice president of Iran, had confirmed positive for the virus last week and has been in home quarantine since.
The country’s Head of Plan and Budget Organization Mohammad Baqer Nobakht had also tested positive for the coronavirus.
Meanwhile, Iran has seen several top officials contract the virus over past months, including First Vice President Es’haq Jahangiri and Vice President Masoumeh Ebtekar. A number of cabinet ministers have also tested positive, including Tourism Minister Ali Asghar Mounesan and the former industry minister Reza Rahmani.
Iran has been contending with the deadliest pandemic the world has seen in many decades amid illegal US sanctions, which have seriously hampered efforts to stem the outbreak.
After declining for weeks, the deaths and infections have been on the rise in Iran since the beginning of September.
Health Minister Saeid Namaki said on Sunday Iran plans to make mask-wearing mandatory in public in other large cities after imposing it in Tehran to fight the coronavirus infections.
Mask-wearing became mandatory in public in the capital on Saturday and President Hassan Rouhani announced that violators would be fined, as the country battles a third wave of coronavirus infections.
"It has been decided that this action would start from Tehran and will be extended to other large cities in the coming weeks," Namaki said in remarks carried by state television.
Masks have been compulsory in indoor public spaces since July.
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, teahouses and hair salons in Tehran closed for a week on Oct. 3 in an effort to curb the spread of the virus. The city's Governor General Anoushiravan Mohseni-Bandpey extended the restrictions on Friday for another week.
AP and Reuters contributed to this story.