Britain and Iran have summoned each others envoys after three Iranians were charged with spying in the UK.

The IRNA news agency said the British charge d'affaire was asked on Sunday to give an explanation for what it said was "unjustified" and "politically motivated" arrests.

On Monday, the Foreign Office responded by summoning Tehran's ambassador to the UK following the charges.

Three Iranian men were arrested on 3 May and appeared in court in London on Saturday charged with spying for the Islamic republic.

It said the government "is clear that protecting national security remains our top priority and Iran must be held accountable for its actions".

"The summons follows this weekend's announcement which stated that three Iranian nationals had been charged with engaging in conduct likely to assist a foreign intelligence service," it added.

The alleged spying took place from August 2024 to February 2025, according to the Metropolitan Police.

Police identified them as Mostafa Sepahvand, 39, Farhad Javadi Manesh, 44, and Shapoor Qalehali Khani Noori, 55, all living in London.

A fourth man was arrested on 9 May as part of the investigation, but has been released without charge, the Met said.

The three men, who arrived in the UK between 2016 and 2022, were granted temporary leave to remain after claiming asylum.

It is alleged they carried out surveillance with a view to locating journalists associated with Iran International.

Iran International produces coverage that is critical of the current regime in Iran and has been proscribed in Iran as a terrorist organisation.

"Iran must be held to account for its actions," Home Secretary Yvette Cooper said in a statement following Saturday's charges.

"We must also strengthen our powers to protect our national security as we will not tolerate growing state threats on our soil," she added.

It comes as five other Iranian men were arrested on the same day in London, Swindon, Stockport, Rochdale and Manchester as part of a separate counter-terrorism investigation.

Four of the men - who had been held on suspicion of preparation of a terrorist act - had been released from custody, although the investigation "remains active and is ongoing", police said.

The fifth man was earlier bailed to an unspecified date in May.