Iran said 135 new coronavirus deaths took the country's overall toll to nearly 1,000 Tuesday, as it curtailed celebrations for a fire festival in a bid to contain the disease.

The COVID-19 outbreak in the Islamic republic is one of the deadliest outside China, where the illness originated.

The latest deaths, announced by health ministry spokesman Kianoush Jahanpour in a televised news conference, take the total death toll in Iran to 988.

"The death toll is 988 ... with 1178 new infected people in the past 24 hours, now the total number of infected cases is 16,169 across the country," he said.

Mr Jahanpour also said 5,389 people who were infected had been discharged from hospitals "with general good health".

AP

Since it announced its first two deaths in the holy Shiite city of Qom last month, Iran has taken a series of steps to contain the virus.

However, it has yet to impose any lockdowns and the outbreak has spread to all 31 of the country's provinces.

In its latest attempt to contain the virus, police banned celebrations marking the traditional fire festival Chaharshanbe Soori, that comes before Nowrouz - the Persian New Year.

Iran has also temporarily freed about 85,000 prisoners, including political prisoners, a spokesman for its judiciary says, in response to the coronavirus epidemic.

"Some 50 per cent of those released are security-related prisoners ... Also in the jails we have taken precautionary measures to confront the outbreak," said Gholamhossein Esmaili. 15 million screened

EPA

The latest health ministry figures showed the COVID-19 disease was spreading fastest in Tehran province.

"Reports by more than 56 laboratories indicated that we have had 1,178 new confirmed cases of COVID-19 infection in the past 24 hours," Mr Jahanpour said on Tuesday.

"This brings the total number of confirmed cases to 16,169 as of today noon," he added.

Tehran province recorded 273 fresh cases of infection.

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Alborz, to the west of Tehran, was next with 116 new cases, followed by East Azerbaijan with 78.

"As of this morning, more than 15 million of our countrymen have been screened" for symptoms, he said.

Foreign Minister Mohammad Javad Zarif took to Twitter on Tuesday to say that US sanctions were "impairing" Iran's ability to fight the COVID-19 disease.

The United States began reimposing crippling sanctions on the Islamic republic in 2018 after unilaterally withdrawing from an international accord on its nuclear programme.