Release embassy staff, Brown tells Iran

The bitter row between Iran and Britain deepened yesterday as Gordon Brown condemned the arrest of nine British embassy staff in Tehran as "unacceptable" and "unjustifiable" and demanding that those still held in captivity be freed immediately.

Five of the nine diplomatic staff, all Iranian nationals, seized on Sunday have been released but the others are still being interrogated. The Prime Minister warned Iran that the European Union had agreed to a "strong, collective response" to any "harassment and intimidation" against EU missions. Separately, the Italian Prime Minister Silvio Berlusconi warned that G8 leaders were likely to adopt new sanctions against Iran when they meet for their summit in Italy on 8 July.

The European rhetoric toughened as Iran's highest legislative body confirmed the landslide election victory declared for the incumbent President Mahmoud Ahmadinejad. The Guardian Council's decision followed a partial recount of votes. According to the official IRNA news agency, the recount in one Tehran district gave Mr Ahmadinejad more votes than in the 12 June poll that unleashed the worst unrest since the 1979 revolution.

The Iranian Intelligence minister, Gholamhossein Mohseni-Ejei, has claimed the British embassy played a role in orchestrating the unrest which followed the disputed election. "They had a crucial role in the recent unrest both through ... local staff and via media," he said. "The embassy sent staff among the rioters to direct them in order to escalate the riots so that the rioters could file fabricated reports about the [rallies] to the world from various locations."

The Foreign Office in London has strongly refuted the allegations and David Miliband, the Foreign Secretary, has spoken about the deteriorating situation with his Iranian counterpart, Manoucher Mottaki. Personal details of those arrested have not been released but at least one is believed to be involved in monitoring the local media – a standard practice in foreign legations throughout the world.

Iran and Britain have already expelled two of each other's diplomats. Last week, Mr Mottaki said that the Islamic Republic was considering downgrading relations with London. However, Hassan Qashqavi, a foreign ministry spokesman, took a more conciliatory line yesterday, saying closing down any foreign embassy or reducing diplomatic ties was not on Tehran's agenda.

Meanwhile, Mr Ahmadinejad has ordered an inquiry into the suspicious death of Neda Agha-Soltan, a woman shot dead during a protest in Tehran. He wrote to the chief of Iran's judiciary, requesting an investigation to identify and prosecute "the elements behind the heart-breaking incident".