Coronavirus has claimed 77 lives in Iran, officials said on Tuesday, as the emergency services chief became the latest high-ranking official to be infected in the deadliest outbreak outside China.

Iran has scrambled to halt the rapid spread of the virus, shutting schools and universities, suspending major cultural and sporting events, and cutting back on work hours.

On Tuesday it announced another 11 deaths and 835 new infections — the biggest increase in a single day since the COVID-19 outbreak began in the Islamic republic nearly two weeks ago.

“According to the latest figures, 835 new patients have been added” to the overall number of infections, Iran's stand-in deputy health minister Alireza Raisi said.

“Unfortunately, we have 11 new deaths, and with this amount we have reached 2,336 new confirmed cases and a total of 77 dead,” he said in remarks aired live on state television.

The national emergency services chief Pirhossein Kolivand was the latest high-profile official to contract the illness, a spokesman for the services told AFP.

Confirmation of his infection came a day after Tasnim news agency reported that the virus claimed the life of Mohammad Mirmohammadi, 72, a member of the Expediency Council which advises Iran's supreme leader.

It also comes a week after the country's original deputy health minister, Iraj Harirchi, fell ill with COVID-19. Harirchi admitted he had tested positive a day after he had coughed and wiped sweat from his brow during a news conference that was beamed live around the country on February 25.

UK-Iranian prisoner 'in perfect health'

But the judiciary said a jailed British-Iranian woman, whose husband said she feared she had been infected behind bars in Tehran, was “in perfect health”.

Nazanin Zaghari-Ratcliffe, who was arrested at Tehran airport in April 2016, is serving a five-year term for sedition at Evin prison.

“Yesterday she talked to her family by phone. There has been news about her recently that was fake news,” judiciary spokesman Gholamhossein Esmaili said.

Iran announced on February 19 its first two deaths from the coronavirus in Qom, a centre for Islamic studies and pilgrims from abroad.

The country now has the highest death toll for any country outside China, where the virus has killed more than 2,900 people since late December.

Supreme leader Ayatollah Ali Khamenei called on Iranians to stick to hygiene guidelines to prevent the novel coronavirus from spreading.

“The health care guidelines for preventing infection from this virus should be observed,” said Khamenei, who was seen on state television wearing gloves as he planted a tree.

Khamenei said Iran was being transparent with its figures on the outbreak and accused other countries of trying to conceal them.

“The #Coronavirus has affected many countries,” he was quoted as saying on his official Twitter account. “Our officials have reported with sincerity and transparency since day one.

“However, some countries where the outbreak has been more serious have tried to hide it. Of course, we ask God to heal the sick in those countries too,” he added.

Iran on Saturday dismissed a BBC Persian report that the real number of coronavirus deaths in the country was more than 200.

The United States and Paris-based media watchdog Reporters Without Borders have accused Iran of concealing information about the outbreak.