Ghoncheh Habibiazad
Senior reporter, BBC Persian

A heavy security presence is in place in Tehran and Karaj, sources have said.

Businesses are struggling to hold up right now with the internet outage, a contact who lives near Tehran tells me.

They said that they had been speaking to a manager of a company in Iran reliant on the internet, who went to the relevant authorities to check on the internet situation.

The manager was told that no-one knows when it will be back and thinks that unless the blackout is lifted, they can only keep the company running for another week at most.

The source tells me that “this situation and the ongoing internet shutdown increase the likelihood of unrest. A lot of businesses are online, and many programmers work remotely.”

Image source, Getty Images

Internet tracking agency NetBlocks says Iran remains offline as the internet blackout passes its 132nd hour.

The blackout - imposed by Iranian authorities - is stopping most Iranians from contacting the outside world, making it difficult to verify what's happening inside the country.

It began last Thursday, after videos from protests were posted on social media, and eye-witness accounts from Iranians on the ground were reported to foreign journalists.

Shekhi is asked how different in scale and speed to which Iranian authorities are carrying out the crackdowns compared to previous protests in years gone by.

"The previous protests we saw crackdowns but not as severe as this time," Shekhi tells Today.

"We have never witnessed this scale of mass killings in the big cities like Tehran.

"We believe that Iranian government is doing all of this to spread more fear among the people, to kind of use this to control the population, to not allow any more protests to happen."

We've just heard from Awyer Shekhi, from Kurdish human rights organisation Hengaw, who says she's afraid there are "many" cases like Erfan Soltani - an Iranian protester who is expected to be executed today.

But because of the internet blackout, the human rights group does not have information about others who may have been sentenced to death, Shekhi tells Radio 4's Today programme.

Shekhi says Erfan's sister, a lawyer, tried to pursue her brother's case but was told by authorities that there was no case to pursue.

The Iranian authorities have told the family they will allow a final meeting with Erfan before his execution, Shekhi says. Though since his arrest he hasn't been allowed any contact with his family, she adds.

"He's just someone who's against the current situation in Iran... now he's received a death sentence for expressing his opinion," she says.

"To all Iranian patriots, keep protesting," the US President said during a speech in Michigan on Tuesday.

Trump urged Iranians to "take over institutions" and to remember the names of "killers and abusers" - as they will "pay a very big price".

Reviving his vow that the US would come to the rescue of Iranian civilians protesting against the government, he also pledged that "help is on the way".

When asked to clarify this by the BBC's US partner CBS News, Trump said: "There's a lot of help on the way, in different forms, economic help from our standpoint, and we're not going to help Iran very much."

Referencing the deaths of protesters in Iran, the president said "it looks like a pretty substantial number".

Asked about reports that protesters are due to be executed on Wednesday, Trump said the US will take "very strong action if they do such a thing".

Image source, The Hengaw Organization for Human Rights

A relative of Iranian protester Erfan Soltani, who was detained by Iranian authorities last week, says he is expected be executed today.

Reports indicate that a death sentence has been handed down to Soltani, 26, after he was allegedly involved in protests near the Iranian capital Tehran.

A relative told BBC Persian that Soltani was arrested on Thursday, the day when protests in Iran reached their peak.

“In an extremely rapid process, within just two days, the court issued a death sentence," the relative said, adding the family was told he was due to be executed Wednesday, 14 January.

Awyar Shekhi, from the Hengaw Organisation for Human Rights, said her teams "have never seen a case move so quickly".

Shekhi is due to speak to Today on BBC Radio 4 after 07:00 GMT. We will bring you the latest lines from that interview.

The latest estimate on the number of people killed in the nationwide protests in Iran stands at 2,571 - according to the American-based Human Rights Activists News Agency (HRANA).

It is an increase of several hundred compared to the figure last verified by HRANA on Tuesday afternoon.

According to HRANA, its latest total figure includes 2,403 protesters, 147 government-affiliated individuals, twelve people aged under 18 and nine non-protester civilians.

The BBC has not independently verified these figures. Most international news organisations, including the BBC, are restricted from operating inside the country.

Image source, Reuters

We're resuming our coverage of Iran's crackdown against weeks of anti-government protests as Donald Trump warns of "strong action" if demonstrators are executed.

"If they hang them, you're going to see some things," Trump told the BBC's US partner CBS News, as a rights group says more than 2,400 anti-government demonstrators have been killed in response to protests.

Relatives of 26-year-old protester Erfan Soltani, who was detained last week, have told BBC Persian that he is due to be executed on Wednesday.

Awyar Shekhi, a representative of the Hengaw Organization for Human Rights, says that the case demonstrates the Iranian government is "using every tactic they know to suppress people and spread fear".

Iran's ambassador to the UN has accused Trump of inciting violence, after he urged Iranians: "KEEP PROTESTING - TAKE OVER YOUR INSTITUTIONS!!!

Stay with us as we bring you the latest developments.