TEHRAN, July 24 — Iran’s judiciary chief today accused the United States of holding Iranians "in gruesome prisons”, as the two countries trade charges of illegally jailing each other’s citizens.

"You are keeping our innocent citizens in gruesome prisons. This is against the law and international norms and regulations,” said Sadegh Larijani, head of the judiciary, quoted by Iran’s state broadcaster.

"We tell them that you must immediately release Iranian citizens locked up in US prisons.”

Washington reacted angrily to news last week that Xiyue Wang, a Princeton University researcher, had been sentenced in Iran to 10 years in prison for espionage.

President Donald Trump warned of "new and serious consequences” unless US nationals held in the Islamic republic were released.

Iranian officials have in turn responded by criticising the detention of Iranians in the US.

Foreign Minister Mohammad Javad Zarif accused Washington of holding Iranians on "charges of sanction violations that are not applicable today... for bogus and purely political reasons”, at a meeting of the Council on Foreign Relations think-tank in New York last week.

Larijani also criticised the seizure of Iranian assets in the United States, such as a recent ruling to seize a Manhattan skyscraper to compensate victims of terrorism.

"They confiscate the assets of the Islamic republic. This is a blatant robbery. Americans behave as a bully and they want to oppress people of other countries,” he said.

At least three US nationals are currently being held in Iran, including father-and-son businessmen Samak and Baquer Namazi. — AFP