Britain and Iran summoned each other’s diplomats in London and Tehran on Monday after British authorities charged three Iranian nationals under a national security law following a major counter-terrorism investigation.
Britain said it had summoned Iranian Ambassador Seyed Ali Mousavi to appear at its foreign office, while Iran summoned the British charge d’affaires in Tehran over the arrests of its nationals, calling the accusations “false claims”.
The three men appeared in court in London on Saturday, charged with engaging in conduct likely to assist a foreign intelligence service between August 2024 and February 2025. British police have said the foreign state in question is Iran.
Four other Iranians were arrested earlier this month in a separate case. Police said on Saturday that they had been released but that the investigation was still ongoing.
The charges come at a time of intense scrutiny of suspected Tehran-backed activity in Britain, with London recently placing Iran on the highest tier of its foreign influence register.
“The UK Government is clear that protecting national security remains our top priority and Iran must be held accountable for its actions,” Britain’s foreign office said.
Iranian state media reported that the British diplomat had been summoned to provide an official explanation for the arrest of Iranian citizens.
“The responsibility for the inappropriate effects of such actions, which appear to be motivated by political motives to exert pressure on Iran, will lie with the British government,” state media quoted a foreign ministry official as saying.