Image copyright Reuters Image caption The justice department released details just under two weeks after the pair were arrested

Two Iranians have been charged in the US with spying for the Tehran government - photographing Jewish institutions and collecting information on the Iranian opposition.

The two, Iranian-US citizen Ahmadreza Mohammadi Doostdar and Majid Ghorbani, an Iranian living in California, were arrested on 9 August.

Details of the case have only now been released by the US justice department.

The case coincides with an increase in tension between the US and Iran.

Washington is reimposing sanctions on Iran after President Donald Trump's decision to withdraw from the multinational deal with Iran aimed at curbing its nuclear ambitions.

"Doostdar and Ghorbani are alleged to have acted on behalf of Iran, including by conducting surveillance of political opponents and engaging in other activities that could put Americans at risk," said Assistant Attorney General for National Security John Demers.

What are they accused of?

In or around July 2017, Mr Doostdar, 38, travelled to the US from Iran to collect information about organisations Iran sees as enemies, the indictment alleges.

These included Jewish and Israeli interests and the opposition Mujahideen-e Khalq (MEK), which Iran calls a terrorist organisation bent on overthrowing the government.

Who are the Iranian dissident group MEK?

Mr Doostdar took photographs of the Jewish Rohr Chabad House, including its security features, it is alleged.

Mr Ghorbani, 59, attended an MEK rally in New York in September of last year, the documents say, where he photographed people taking part in a protest against the Iranian leadership.

Three months later, he was paid $2,000 (£1,500) by Mr Doostdar for the photographs, many with notes about the individuals pictured.

Image copyright EPA Image caption Relations between the US and Iranian leaders are tense

The transaction took place in the Los Angeles area after Mr Doostdar returned from a visit to Iran, prosecutors say.

According to the indictment, the pictures and a receipt for $2,000 were found in his luggage at a US airport as he returned to Iran last December.

Mr Ghorbani is said to have made a trip to Iran in March 2018 to give an "in-person briefing" and receive instructions on infiltrating the MEK.

Two months later, he is alleged to have attended an MEK-linked Iran Freedom Convention for Human Rights in Washington.

He is said to have photographed speakers and others attending before discussing with Mr Doostdar how to covertly get the information back to Iran.

What are they charged with?

Knowingly acting as agents of the government of Iran without prior notification to the attorney general

Providing services to Iran in violation of US sanctions

Conspiracy

If found guilty they could face up to 20 years in jail.

The stiffest penalty would be for violating the International Emergency Economic Powers Act - used to restrict commerce with Iran.