The British government summoned Iran's most senior diplomat in London on Monday to protest what it said were serious threats against journalists living in Britain, as ministers launched a new security review into Iranian activities.
On Saturday, a London-based television station critical of the Iranian government said it was moving its live broadcasting studios to the United States after threats it faced in Britain.
"I am appalled by the Iranian regime’s continuing threats to the lives of UK-based journalists and have today summoned its representative to make clear this will not be tolerated," Foreign Secretary James Cleverly said in a statement.
The foreign office said the Iranian Charge d’Affaires had been told in a meeting with British officials that Britain would not accept such threats to life and media freedom.
Earlier, the government imposed sanctions on three Iranian judges, three members of Iran's Revolutionary Guard Corps and two regional governors over what it said were human rights violations.
Britain, along with the European Union and the United States, has strongly criticized a widespread and often violent crackdown on popular protests after the death of young Iranian Kurdish woman Mahsa Amini in police custody in September.
Tehran accuses Western adversaries of stoking the nationwide unrest ignited by Amini's death.
In a separate statement, British security minister Tom Tugendhat said he had ordered a government review led by the interior ministry into state threats coming from Iran.
"We will target the full spectrum of threats that we see coming from Tehran," Tugendhat told parliament.
"I'll be asking our security agencies to explore what more we can do with our allies to tackle threats of violence. But we will also address the wider threat; from economic security and illicit finance to the malign interference in our democratic society."
In November, Britain's domestic spy agency head said Iran's intelligence services have tried on at least 10 occasions to kidnap or even kill British nationals or individuals based in the United Kingdom regarded by Tehran as a threat.
