Iran is limiting travel between its major cities as it tries to halt the spread of the coronavirus, which has killed at least 107 people there.
The country has already shut schools until April, and Health Minister Saeed Namaki said people should not use the break as an opportunity to travel.
He also urged Iranians to reduce the use of paper banknotes.
The measures come as the World Health Organization warned some countries were not doing enough to stop the virus.
But WHO chief Tedros Adhanom Ghebreyesus insisted containment was still possible, adding: "This is not a time to give up."
Iran is one of the worst-hit countries outside China, where the Covid-19 virus – which causes the coronavirus disease – originated.
Worldwide, authorities have confirmed more than 92,000 cases of the virus, of which more than 80,000 are in China.
More than 3,000 people have died globally, the vast majority of them in China.
What do I need to know about the coronavirus?
- WHAT ARE THE SYMPTOMS? A simple guide
- WAYS TO PREVENT CATCHING IT: How to wash your hands
- WHERE ARE WE WITH A VACCINE? Progress so far
- A VISUAL GUIDE TO THE OUTBREAK: Virus maps and charts
What's the latest from Iran?
The country's official death toll on Thursday rose by 15 to 107, and the number of confirmed cases increased by 591 to 3,513.
But state news agency Irna said the number of dead could be higher, citing data from medical universities.
The data did not include statistics from the capital Tehran and Gilan province – two of the hardest-hit areas. The toll there was listed as "unknown", Irna said.
Last month sources in the country's health system told BBC Persian the death toll was at least 210, with most victims in Tehran and the holy city of Qom.
Mr Namaki said checkpoints would go up to limit travel between major cities.
In a televised press conference, he said travel was "very dangerous" and reports showed "many cars on the roads are taking the virus with them" to uninfected areas.
He added that schools and universities would remain closed until Nowruz, the Persian new year, on 20 March, which marks the beginning of a national holiday.
"People should not consider this as an opportunity to go travelling. They should stay home and take our warnings seriously," he said.
"This virus is highly contagious. It is a serious matter, do not joke about it."
How are Iranians reacting?
Ladan, an asthma sufferer in Tehran, told the BBC increased stress was the worst aspect of the outbreak for her so far.
"It feels so unsafe now. I quarantined myself without having any sanitizer. I am starting to see everything like a virus. I feel like I am becoming paranoid about whatever I buy and bring into my house," she said.
In the western city of Hamedan Mohammedreza said the crisis had provoked an "epidemic of fear".
A doctor in western Iran who gave his name as Mehrzad told the BBC his hospital had done nothing to prepare for the outbreak as late as a week ago. He said he had ended up buying extra masks and gloves out of his own pocket.
By contrast, in the central city of Isfahan, Mohammad said very few people were taking the outbreak seriously.
"Many believe it is happening anywhere else but Isfahan. You barely see anyone wearing masks or gloves," he said.
"But what is striking is the food prices, which are rising on a daily basis – and everyone buys more than their needs as if a famine is on its way."
What is happening elsewhere?
- New York state has 22 confirmed coronavirus cases, Governor Andrew Cuomo says. Eighteen US states now have cases
- Read More – Source