US President Donald Trump has said the US will take "very strong action" against Iran if it executes protesters, as rights groups say more than 2,400 anti-government demonstrators have been killed in a violent crackdown by Iranian authorities,
BBC reports.
Relatives of 26-year-old Erfan Soltani, who was detained last week, told BBC Persian he was due to be executed on Wednesday. It is unclear whether this has taken place.
A representative from the Hengaw Organization for Human Rights also told the BBC that they had "never witnessed a case move so quickly".
Speaking to the BBC's US partner CBS News, Trump said of potential executions: "If they hang them, you're going to see some things... We will take very strong action if they do such a thing."
Soltani's relative told BBC Persian that an Iranian court had issued a death sentence "in an extremely rapid process, within just two days".
They were "deeply concerned that he could be executed without any prior notice", given that contact with Iran has been affected by the internet shutdown.
Soltani's detention demonstrated that the Iranian government was trying "to control the population, to not allow any more protests to happen", Hengaw representative Awyar Shekhi told the BBC's Radio 4 Today programme on Wednesday.
Soltani's sister - who is a lawyer - tried to intervene in his case but was told by authorities there was nothing to pursue, Shekhi added.
Prisoners sentenced to death in Iran are typically granted final moments with loved ones. While the Iranian authorities have told the family they will allow a meeting with Erfan before his execution, Shekhi said, he hasn't been allowed any contact with his family since his arrest.
An Iranian official told Reuters that 2,000 people had been killed, but that "terrorists" were to blame.
Trump earlier said he planned to attend a meeting at the White House on Tuesday night to discuss the situation in Iran, pledging to get "accurate numbers" on the death toll from the protests.
"The killing looks like it's significant, but we don't know yet for certain," Trump told reporters while returning to the White House.
Once he has the numbers, he said, "we'll act accordingly."
The US-based Human Rights Activists News Agency (HRANA) said that it had so far confirmed the killing of 2,403 protesters, as well as 12 children, despite an internet blackout. Nearly 150 people affiliated with the government have also been killed, the group said.
State-linked Iranian news agency Fars reported that funerals were held in Tehran on Wednesday for more than 100 members of the security forces and others they described as "martyrs".
