Thousands of Iranians drove through the capital Tehran on Wednesday to mark 42 years since the Islamic revolution, but stayed in vehicles rather than marching on foot amid pandemic restrictions.

Due to Covid-19, state television said that this year there should be "no gathering or marching" to celebrate the 1979 overthrow of the shah's regime.

Instead, people travelled by cars, motorcycles and bicycles, to gather in Tehran's iconic Azadi Square.

Some had painted their cars in the red, white and green colours of the Iranian flag. People chanted the slogan "Death to America" from vehicle windows.

"Only the form... has changed this year, not its nature," said a correspondent on state television, which broadcast footage of similar rallies in other major cities, including Shiraz, Qom, Isfahan and Mashhad.

Protesters carried portraits of Iran's supreme leader Ayatollah Ali Khamenei, as well as Iran's revered General Qasem Soleimani, killed in an American airstrike in Baghdad in January 2020.

Replica ballistic missiles and Iranian-made military equipment were also paraded.

The coronavirus has infected nearly 1.5 million people in Iran and killed more than 58,000, according to the health ministry. 

Iran, which has a population of over 80 million, is the country hardest hit by the pandemic in the region.

It began its Covid-19 vaccination campaign on Tuesday, using Russia's Sputnik V jab.

Alongside the pandemic, Iran remains mired in an economic crisis, triggered by the decision of former US president Donald Trump to withdraw from a landmark 2015 nuclear deal and reimpose crippling sanctions from 2018. 

The administration of US President Joe Biden -- who was inaugurated last month -- has expressed willingness to return to the deal, but has insisted that Tehran first resume full compliance.

Iranian President Hassan Rouhani on Wednesday praised citizens for "their patience in the face of three years of suffering" due to Trump's "maximum pressure" policies, including economic sanctions.

"The era of maximum sanctions is over, the era of economic warfare is over," Rouhani said in a televised speech, adding that "everyone has realised that maximum pressure has failed".

Biden has said he won't lift sanctions against Iran as long as the Islamic republic is not adhering to its nuclear deal commitments.

But Iran demands sanctions are lifted before it return to its commitments.