Iran's health ministry raised on Sunday the nationwide death toll from the new coronavirus to 54 as the number of confirmed infected cases jumped overnight by more than half to 978 people.
The ministry's spokesman Kianoush Jahanpour said new cases were confirmed in a number of cities, including Mashhad, which is home to Iran's most important Shiite shrine that attracts pilgrims from across the region.
Calls by Iran's civilian government to clerics to close such shrines to the public have not been uniformly followed.
The shrine in Mashhad is among those that have remained open.
The new figures represent 11 more deaths than reported on Saturday and a whopping 385 new cases of infections.
The new numbers, however, bring down the percentage of deaths to infections to around 5.5%.
Still, that is much higher than in other countries, suggesting the number of infections in Iran may be much higher than current figures show.
Jahanpour said in his daily briefing that the number of cases is "still inclining" across Iran.
Of the 385 newly confirmed cases, 170 are in Tehran, where schools and cinemas have remained closed for the second week.
Public buses and the metro are still operating, but are being disinfected daily there.
The ministry spokesman said that 44 cases were also confirmed for the first time in the central Markazi province.
Also on Sunday, Iran's state broadcaster said all flights to and from the city of Rasht, the capital of northern Gilan province, had been suspended.
The area of Gilan has some of Iran's highest number of infections after the capital, Tehran, and the holy city of Qom, the epicenter of the virus outbreak in the country.
The Revolutionary Guard said it plans to install mobile hospitals in the cities of Qom and Rasht cities. The Guard has also been photographed in state media leading disinfection efforts in some cities.
The illness, known as COVID-19 and that originated in central China, has infected at least seven government officials in Iran, including one of its vice presidents and a senior health ministry official.
After days of assurances that the virus was largely under control, officials recently acknowledged Iran is preparing for the possibility of "tens of thousands" of people getting tested for the virus behind the outbreak.
The first cases were not reported in Iran until Feb. 19, the same day that the two elderly infected people died.
Since then, of the more than 1,100 cases in the Middle East, the majority trace back to Iran.
Cases from Iran have been reported in Kuwait, Bahrain, Oman, the United Arab Emirates, Qatar, Lebanon, Afghanistan, Iraq and Pakistan.
Starting on Sunday, all nurseries in the UAE licensed by the education ministry were closed for at least two weeks to limit the spread of the virus, and Kuwait suspended school until March 12.
The virus has infected more than 86,000 people worldwide and caused more than 2,900 deaths since emerging in China. Iran has the world's highest death toll outside of China, where there have been 2,870 deaths among close to 80,000 cases.
The outbreak in Iran has prompted its neighbors to seal their borders to Iranians, while other Gulf states have halted flights to Iran.
On Saturday, the U.S. announced heightened warnings about travel to certain regions of Italy and South Korea, as well as a ban on travel to Iran, due to the virus.
Islam's holiest sites in Saudi Arabia have been closed to foreign pilgrims to limit the spread of the virus. The kingdom does not have any reported cases of the virus, and has halted all flights to and from China and Iran.
One of the most important Shiite shrines in the world in Iraq's Najaf city has also closed to Iranian pilgrims after a student from Iran studying there was confirmed to have the highly infectious virus.